Max Verstappen has cast further doubt over his Red Bull future after suggesting that he will quit Formula One’s dominant team if motorsport adviser Helmut Marko is forced out.

The PA news agency understands 80-year-old Austrian Marko, an instrumental figure in Verstappen’s career, faces a Red Bull investigation following the probe into claims of “inappropriate behaviour” against Christian Horner.

Horner’s female accuser was suspended earlier this week as a direct result of Red Bull’s inquiry which exonerated the 50-year-old team principal.

Marko is employed by the F1 team’s parent company, Red Bull GmbH. Asked if he could be suspended following Saturday’s Saudi Arabian Grand Prix, he told Austrian broadcaster ORF: “Ultimately, I’ll decide for myself what I do. The theoretical possibility always exists.”

PA has approached Red Bull Racing for comment.

Red Bull’s three-time reigning world champion Verstappen, speaking after qualifying on pole for Saturday’s race in Jeddah, said: “I have a lot of respect for Helmut, and what we have achieved together.

“It goes very far. My loyalty to him is very big, and I have always expressed this to everyone within the team, everyone high up, that he is an important part in my decision-making for the future.

“It is very important that he stays. I feel like if such an important pillar falls away, and I have told the team this, that it is not good for my situation as well.

“Helmut built this team together with (Red Bull’s late owner and founder) Dietrich (Mateschitz) from day one, and he’s always been very loyal to the team.

“It is very important that you give the man a lot of respect for what he has done, and that comes back to loyalty and integrity, so it is important that he stays.”

Verstappen did not mention Horner’s name as he defended Marko.

Horner, team principal at Red Bull since 2005, said on Thursday he is certain Verstappen will see out his long-term contract with Red Bull, despite the ongoing controversy.

Verstappen’s father, Jos, claimed Red Bull will “explode” if Horner remained in his role.

Verstappen, whose deal runs until 2028, has been linked with a move to Mercedes to replace Lewis Hamilton next season. Hamilton said earlier this week that the 26-year-old Dutchman is on Mercedes’ “list”.

Lewis Hamilton believes that Max Verstappen is a serious contender to replace him at Mercedes next season.

A vacancy has opened up at the Silver Arrows following Hamilton’s shock decision to join Ferrari.

The apparent division at Red Bull – following the very public spat between team principal Christian Horner and Verstappen’s father, Jos – has led to speculation that the Dutch driver, despite being under contract until 2028, could quit the team which has carried him to the past three world championships.

“My move has shown that anything is possible,” said Hamilton ahead of this weekend’s Saudi Arabian Grand Prix. “I know and I am sure Max is on the list.”

Hamilton and Verstappen’s relationship soured in 2021 as they fought for the world title – with Verstappen taking the championship following a deeply contentious end to the season decider in Abu Dhabi. Tensions were also high between Mercedes and Red Bull.

But Hamilton continued: “I wouldn’t say I am surprised that he is being considered. He is a great driver.

“And Max in that moment did what he had to do. It was nothing on him. It was the sport that let us down and that wasn’t his fault. If I was in his position I would have done the same thing, so there are no issues there.

“If you run a team you want the best driver and a driver that brings in the eyeballs and brings in the sponsorship and he is one of those. I understand it but it wouldn’t make sense for him, but it will be interesting to see.

“George (Russell) is an integral part of this team and he will be here for the long haul. He is doing a great job and he will grow to be a leader of this team so it will be interesting to see what their relationship looks like but I am sure they will work it out.

“It will definitely be a strong line-up.”

Earlier, Russell said he would welcome the challenge of going up against Verstappen, who has won 18 of the last 19 races and is the overwhelming favourite to claim another victory in Jeddah on Saturday night.

“This is my third season alongside Lewis, the greatest of all time and I feel like I have done a pretty good job alongside him,” said Russell.

“So, whoever were to line up alongside me, I welcome the challenge.

“You want to go against the best. I believe I can beat anybody on the grid. Having Lewis as my benchmark has been a good benchmark for sure.

“Any team wants to have the best driver line-up possible and right now Max is the best driver on the grid.

“If any team had a chance to sign Max they would 100 per cent be taking it but the question is on his side and Red Bull’s side and we don’t know what is truly going on behind closed doors and it is none of our business. But it would be exciting.”

Max Verstappen stood by his father Jos, saying “he is not a liar” following his explosive claim that Red Bull could explode if Christian Horner remains as team principal.

Speaking ahead of this weekend’s Saudi Arabian Grand Prix, Verstappen was asked if his father regretted his remarks, which not only cast further doubt over Horner’s future, but of his son.

“I have not asked him that but my dad, from how I know him in go-karting, is very outspoken and he is not a liar, that is for sure.

“My dad and I are very close. We call every day.”

Verstappen’s manager Raymond Vermeulen met with Horner earlier this week in an attempt to clear the air at the crisis-hit team. Neither Max, nor Jos, were present.

And Verstappen added: “I don’t see myself in F1 without them (his father and manager) by my side.”