Lewis Hamilton was well off the pace as Mercedes were jolted by their "poor start" to testing ahead of the new Formula One season.

Gearbox trouble meant Valtteri Bottas could only complete six laps in the morning in Bahrain, before team-mate Hamilton had a clearer run and ran through 42 laps in the afternoon.

However, reigning drivers' champion Hamilton was only 10th-fastest on the day, with Red Bull's Max Verstappen topping the time sheets, while Bottas was the slowest of all the 17 drivers involved.

Mercedes' trackside engineering director Andrew Shovlin declared: "It's been a poor start to the season from us.

"Once we got running it was clear we didn't have the car in the right balance window and, while we made some progress during the day, we're not happy with how the car is performing and it's pretty clear we have some work to do."

The Mercedes W12 is the car with which the team hope to land an eighth consecutive constructors' title, while Hamilton will be chasing a fifth successive drivers' championship and a record eighth overall.

Hamilton said: "Today definitely wasn't the cleanest of days that we've had, but these things are sent to try us.

"Everyone has worked extremely hard to get us here. We had that mishap in the morning which was very unfortunate for Valtteri in terms of losing time on track and the team is working hard to try and understand what that was.

"I think they did a great job to turn the car around. The second session wasn't without its challenges, but we exist to find solutions to the problems we're faced with."

Hamilton was affected by a sandstorm and said Mercedes would look to "take the positives" from their shaky day, with two more days of testing to come.

Positives were not immediately obvious, and Bottas said: "In recent years, things have been pretty much bulletproof so it's not a familiar experience."

However, the Finn added on the team's website: "I am confident we can recover and I’m looking forward to two good days over the weekend."

As well as testing, Bahrain will host the opening grand prix of the Formula One season, with that race scheduled for March 28.

George Russell hopes Williams can make a flying start to the Formula One season in Bahrain - but he believes Mercedes are the only team who will be sure they are race-ready.

British driver Russell caught the eye when he replaced Lewis Hamilton at Mercedes for one race last year, after the world champion tested positive for COVID-19 and missed the Sakhir Grand Prix.

He went close to winning that race until a pit-stop error and a puncture late on cost him a probable victory, and he then returned to his regular drive at Williams.

Mercedes have assured Russell, who is part of their junior driver programme, that he can have a racing future with them if his development continues as expected.

That could come as soon as next year, but for now Russell's focus is on delivering for Williams.

The team has been in transition following the takeover by Dorilton Capital, and German motorsport veteran Jost Capito was appointed chief executive officer during the close season.

Russell believes Williams, who failed to score a point last season, should be better placed in 2021 to at least improve on that disappointing outcome.

"We want, the bare minimum, to be fighting with the Haas and the Alfas, as we did last year, and closing the gap to that midfield," Williams said.

"We made nine out of 17 Q2 appearances and that is definitely a thrill. That's got to be almost an aim every weekend for myself and team."

The season begins in Bahrain on March 28, and by then there should be evidence of which teams have made progress since 2020, with testing taking place, also in Bahrain, on the March 12-14 long weekend.

Russell admits it is a waiting game to see how rivals have advanced, or regressed.

"Fingers crossed that they go backwards and we go forwards," he said, in an Instagram chat on Formula One's official page. 

"Ultimately, we may go to Bahrain and see every other team has progressed more than us.

"We may go there and see we've made great progress. Until we get to Bahrain not a single team, probably bar Mercedes, can tell you how they're going to perform."

Russell, 23, has been tipped for a big future in the sport. He also believes Williams, a great name from the history of Formula One, can begin a journey back to the top of the sport.

"The arrival of Jost is massive for the team, really exciting," he said. "The future for Williams and everybody here at Grove [the team's headquarters] is really great.

"Unfortunately, things don't change in a matter of moments in Formula One, but the building blocks are really getting set in stone.

"Jost has loads of experience, he's a great character, and I think he's going to bring a lot of motivation to the team."

Russell was speaking on the day F1 chiefs confirmed the Portuguese Grand Prix on the new season's calendar, with the race inked in for May 2.

It will be the second round of 23 in the championship, with Portugal having returned to the Formula One rota last year for the first time since 1996.

George Russell has no intention of "hassling" Mercedes over his future as he focuses on trying to get the most out of a new-look Williams car in 2021.  

The British driver is heading into the final year of his contract with Williams, where he will once again work alongside Nicholas Latifi for the season.  

It will be a third year for Russell with the team, though he did step in to drive for Mercedes - having previously been part of their junior driver programme - at the 2020 Sakhir Grand Prix, replacing Lewis Hamilton after the seven-time world champion tested positive for COVID-19. 

His performance in the race - he was in front for the majority before a slow puncture forced him to settle for ninth place - led to speculation over a permanent switch, but Hamilton and Valtteri Bottas have remained together.  

While a move could still happen at some stage further down the line, Russell is relaxed over his standing within Mercedes.  

"Mercedes and Toto have always had my back and believed in me from day one. When they believe the time is right, the time will be right," he told Sky Sports at the launch of Williams' FW43B car.  

"I'm not hassling them, I’m just going out there and doing my job on the track. What comes in the future will come.  

"Obviously I had a great opportunity in Bahrain last year, but for now we will focus on the job here at Williams for this season and trying to get the most out of it."

In a somewhat surprising move, Hamilton only agreed to a one-year extension earlier this year, committing him to a ninth season with Mercedes.

Bottas' deal runs "at last until the end of 2021", per the team's statement when the Finn's future was revealed last August, so Russell could potentially be considered to replace either driver in 2022.

"Every driver wants to put themselves against the best," he said when asked if forming a partnership with Hamilton appealed to him.

"I believe in myself and Lewis is the benchmark at the moment, but equally you have a lot of fantastic drivers out there who might not have the same CV as Lewis.  

"Max [Verstappen], Charles [Leclerc], Lewis – they are all on the same level. Putting yourself against one of those three would be great for any driver."

Williams - now owned by Dorilton Capital - unveiled a new blue, white and yellow livery on Friday that takes inspiration from the team's successful cars in the 1980s and 1990s.

Toto Wolff admitted Max Verstappen is a driver who will be "on everybody's radar" but has vowed Mercedes will not rush to seduce the Red Bull star.

Mercedes team principal Wolff will be aware that reports have linked Verstappen with a possible future move to the Silver Arrows, possibly as a long-term replacement for Formula One champion Lewis Hamilton.

For now, though, Hamilton is going nowhere, having signed a contract for the upcoming 2021 season, and the British driver may yet remain for years to come.

After landing a seventh drivers' title last year to match Michael Schumacher's F1 record, there is no driver that Mercedes would take above Hamilton in the present time.

Wolff said: "The symbiosis that we have in the relationship, it's always that we have a mutual understanding of what we want to do in the future. That will be also the case in the discussions with Lewis going forward.

"Max is certainly an outstanding young driver that will be on everybody's radar in the future, but we are not flirting outside before we have a clear understanding with our two drivers."

Verstappen has finished third in the championship in each of the last two seasons, with the 23-year-old winning races at Silverstone and Abu Dhabi during the 2020 campaign.

He tallied 214 points to finish just nine points behind Mercedes' runner-up Valtteri Bottas in the championship.

Quoted widely after Mercedes unveiled their new W12 car on Tuesday, Wolff underlined how Mercedes are not blinkered about the team's future and the potential for a change of direction.

Bottas is also due to reach the end of his contract after the new campaign, meaning Mercedes currently have flexibility should they wish to reshape their driver line-up for 2022 and beyond.

"Our first discussions are going to be with Valtteri and Lewis in respecting our values, integrity and loyalty - but on the other side the young drivers are the future," Wolff said.

"Therefore we need to consider how we want to set ourselves up for the years beyond."

Lewis Hamilton says his decision to only sign a one-year contract with Mercedes should not cause concern as he prioritises his drive for more diversity in Formula One.

It took until February before seven-time world champion Hamilton and Mercedes finally announced they had come to terms on a new contract.

The agreement was only for 2021, the last season before sweeping regulation changes come into the sport.

Hamilton, 36, insists there should be no doubts over his commitment.

The Briton also spoke of his passion to fight for change and equality in F1 and wider society.

That will serve as his main focus in a year where he could surpass Michael Schumacher outright with an eighth title.

"I'm kind of in a fortunate position where I've achieved most of the stuff I wanted to achieve up until this point, so there's no real need necessarily to plan too far ahead in the future," Hamilton said at the launch of Mercedes' new W12 car.

"I'm fully invested in this season and delivering. I still love what I do.

"We're living through an unusual period of time in life and I just wanted one year. Then we can talk about if we do more, and keep adding it [by] one if we have to.

"I chose to have a one-year deal, so I can see where we are at. It doesn't mean I'm not committed.

"What I'm really focused on - there was a lot of discussion around the diversity issue, what is important is that we are delivering."

Hamilton added: "I'm really proud of my team, I'm already seeing steps to see that progress. That's my driving force to make sure we continue to push for accountability.

"The main priority for 2021 - in the past it was about just winning championships. But now it's really pushing for making real change.

"Last year there was discussion about equality and inclusion and there was a lot of talk this year about pushing for diversity and really making sure that action is taken.

"That's at the core of the drive for me, but of course we exist to win. That is what all these guys and girls here are working towards, so that's my goal to deliver it for them."

Mercedes boss Toto Wolff echoed the comments of Hamilton and is not concerned about the short deal.

Wolff said: "No doubt about his commitment. First of all, he enjoys racing a lot. We enjoy working with each other and we discussed that a lot.

"But he’s absolutely right. The times change, new priorities for all of us in terms of the way we live, our health, he is very passionate about his initiatives against racism and inequality.

"Then we have this massive regulatory change in 2022 that is going to reshape what Formula One will be.

"I don't think this will play a role, but I think it's fair for a driver who has won seven championships to have the flexibility to decide what he wants to do in future.

"We have agreed that we want to pick up the discussions much earlier this year to avoid a situation like we had in 2020, to run out of time and be in the uncomfortable position that we have no time left before the beginning of the season."

The 2021 season is scheduled to get under way with the Bahrain Grand Prix on March 28.

Lewis Hamilton has signed a new contract to race for Mercedes in the 2021 Formula One season, it has been confirmed.

The reigning F1 champion will spend a ninth season with the Silver Arrows after winning a record-equalling seventh drivers' title in 2020.

Mercedes and Hamilton have agreed a deal that includes the formation of a joint charitable foundation with the aim of supporting greater diversity and inclusion in Motorsport.

Hamilton said: "I am excited to be heading into my ninth season with my Mercedes team-mates. Our team has achieved incredible things together and we look forward to building on our success even further, while continuously looking to improve, both on and off the track.

"I'm equally determined to continue the journey we started to make motorsport more diverse for future generations and I am grateful that Mercedes has been extremely supportive of my call to address this issue.

"I'm proud to say we are taking that effort further this year by launching a foundation dedicated to diversity and inclusion in the sport. I am inspired by all that we can build together and can't wait to get back on the track in March."

Team principal Toto Wolff added: "We have always been aligned with Lewis that we would continue, but the very unusual year we had in 2020 meant it took some time to finish the process.

"Together, we have decided to extend the sporting relationship for another season and to begin a longer-term project to take the next step in our shared commitment to greater diversity within our sport.

"Lewis' competitive record stands alongside the best the sports world has ever seen, and he is a valued ambassador for our brand and our partners.

"The story of Mercedes and Lewis has written itself into the history books of our sport over the past eight seasons, and we are hungry to compete and to add more chapters to it."

In a 2020 season that was truncated due to the coronavirus pandemic, Hamilton still made history by breaking Michael Schumacher's all-time F1 wins record with his 92nd victory at the Portugal Grand Prix.

This year he will hope to surpass Schumacher and become the first F1 driver in history to win eight world titles.

The 2021 season is scheduled to get under way with the Bahrain Grand Prix on March 28.

Lewis Hamilton has signed a new contract to race for Mercedes in the 2021 Formula One season, it has been confirmed.

Ferrari do not regret their failure to sign Lewis Hamilton for the 2021 season as they are confident Charles Leclerc can challenge the Formula One champion.

Hamilton has won six of his record-equalling seven world championships with Mercedes, although he has not yet committed to the Silver Arrows for the coming campaign.

A resolution is expected soon, but links to rivals Ferrari have never been far away.

A blockbuster move will not materialise on this occasion, however, as the Scuderia have secured Carlos Sainz Jr next to Leclerc in their 2021 line-up, replacing Sebastian Vettel.

And team principal Mattia Binotto is confident they have made the right move.

He told Sky Sports: "I don't think there will be regret because, at the end, when we took some decisions, we took them thinking they were the right decisions and today we have a fantastic driver like Charles, where we invested a lot as Ferrari.

"I think he's got a lot of talent. If he's got the right car, I'm pretty sure he can challenge Lewis Hamilton.

"We've made our choices and I think, together with Carlos, we are very strong. I don't think there will be any regret."

Although Leclerc - fourth two years ago with two wins to his name - would appear the obvious Ferrari contender, Binotto is not naming a "number one".

Sainz finished seven points better off than his new team-mate in 2020 while still with McLaren.

"There is not a number one and number two," Binotto said. "They will have equal opportunities - certainly at the start of the season. I'm pretty happy then that they are free to fight.

"I think what we have to do as usual is to optimise the team points, and when you optimise the team points, normally you are optimising the drivers' points as well. Team points is the number one.

"Later in the season, let's see how things will progress, let's see what objectives individual drivers can maybe achieve and if we need to adopt a different strategy, but at the start of the season, they will be free to fight."