Toto Wolff says budget cap breaches would be a 'heavyweight' issue for Formula One

How Verstappen can be crowned F1 champion in Singapore (2:06)

Laurence Edmondson and Nate Saunders debate the likelihood of Max Verstappen winning the F1 title in Singapore. (2:06)

SINGAPORE -- Mercedes team principal Toto Wolff says Formula One faces a "heavyweight" issue amid claims Red Bull and Aston Martin exceeded the sport's cost cap in 2021.

After several months of analysing all 10 teams' accounts, the FIA is set to issue certifications to those that met the $145 million budget cap last year.

In an interview with Sky Sports after Friday practice at the Singapore Grand Prix, Wolff said it was a serious issue for the sport's governing body to tackle.

"It's heavyweight," he said. "That's massively heavyweight.

"We are using used parts, we are not running what we would want to run, we are not developing what we could be developing. We've made more than 40 people redundant that are dearly missed in our organisation.

"It was a huge mammoth project to make the cap. I don't know how many tens of millions we had to restructure and reprocess to be below the cap. If someone has not been doing that, or pushing the boundaries, every million is a massive disadvantage."

Red Bull team boss Christian Horner also spoke to Sky Sports in Singapore, saying the accounts the team submitted were within the budget cap and he is confident they are compliant with the rules.

"We're certainly not aware of any [breach]," Horner said. "The accounts were submitted back in March, so it's been a long process with the FIA. We're in that process as we speak.

"They're rightly following that process and I think next week is when they declare their certificates. Our submission was below the cap, and it's down to the FIA to follow their process, which they're currently doing."

In response, Wolff added: "It's funny that Christian says that, because it's weeks and months that they are being investigated. Maybe he doesn't speak to his CFO.

"All of us have been investigated diligently and as far as we understand, there's a team in [a] minor breach which is more procedural and another team that is fundamentally massively over. That is being look after, that's an open secret in the paddock."

The issue is a contentious one as Max Verstappen narrowly beat Lewis Hamilton to the title last year after an already-controversial season finale in Abu Dhabi. However, Wolff said exceeding the budget cap last season -- in a year when all teams were simultaneously fighting for the 2021 title while designing new cars for F1's new regulations -- would have a major impact on this season, and possibly 2023 as well if rumours Red Bull has already designed a lightweight chassis for next year are true.

"The crucial part is that if you're over in 2021, you're over in 2022," he said. "That means that you have an advantage into 2023.

"If it's true they've homologated a lightweight chassis this year, they may use it next year. It's a real cascade of events that can be influential in all the championships."

It is not yet clear what punishment teams will face if they are found to have exceeded the cost cap, although two sets of possible punishments exist depending on whether the overspend is within 5% of the original cap or above.

Possible penalties for overspend under 5% include a public reprimand, a deduction in points (both for constructors and drivers), suspension from stages of rounds of the championship, limitations on the ability to conduct aerodynamic testing and a reduction in the cost cap for the following year. Possible penalties for overspend beyond 5% include all of the above as well as exclusion and suspension from championships.

"Even if it is the so-called minor breach, under 5%, you can spend 7 million more than everyone else, and this means if this is a light penalty we will all be pushing those 5% going forward," Wolff said.

"You need to imagine, we have a pool of $140 million. If you're spending 5 or 10% more than everyone else, that's many, many tenths of a second. We couldn't reduce our overweight which is double-digits this year, because we simply didn't have the money to produce and put on the new parts. You're fighting a totally different league if you've been pushing the limit upwards."