Four-time Formula 1 world champion Max Verstappen has accused Red Bull's rivals of breaking the rules despite the Dutchman retaining his crown this season.
The Red Bull star kept his vice grip on the F1 throne but found himself under mounting pressure as rival teams overtook Red Bull's car in the second half of the campaign.
Not one to mince his words, Verstappen has called on his own team to up their efforts or risk falling further behind in 2025.
McLaren in particular profited from a quicker design this year, and the reigning king of the grid is clearly concerned about Red Bull slipping off the pace.
"There were things that happened in the background, which meant that we had no chance at all in certain races," Verstappen told De Telegraaf in an explosive interview breaking down this season's developments. "I know that for sure, but no one will ever admit that."
The 27-year-old stopped himself short of naming names or going into specifics regarding how the rules had supposedly been bent.
McLaren attracted scrutiny after the mid-season break for a flexing rear-wing design that helped improve downforce.
The innovation was dubbed a 'mini DRS' by some and allowed Lando Norris and Oscar Piastri to make significant speed gains.
Reports later emerged in November alleging the British team was also implenting a new valve to add water to its rear tyres - and other teams were said to have added the same design to their cars.
Red Bull chief Horner gave a simple "no comment" when asked about the accusations lodged against rivals McLaren following the Sao Paulo Grand Prix.
Ferrari team principal Frederic Vasseur was more vocal on the matter but quizzical as he said: "I don't understand the theory because I think we are all trying to remove humidity from everywhere, not to add something into the tyres."
The departure of head engineer Adrian Newey - who will join Aston Martin in 2025 - was always going to have a big impact on Red Bull's designs. But few might have expected the drop-off in results to be quite so instant following his exit midway through 2024.
The FIA did not officially deem McLaren's rear wing design illegal, but the manufacturer was instructed to restrict the amount the element could move.
Both Norris and Piastri defended McLaren before the team agreed to make changes to its rear wing after the FIA decided it was deforming too much on track.
It's exactly that kind of testing of the limits that led Red Bull to become the dominant force in F1 in recent years. Verstappen, meanwhile, also had a warning for his own team.
After suffering toward the back end of last season, he appeared to suggest principal Horner and the Red Bull mechanics need to buck up their ideas to put the team back in a place of superiority.
"If we continue like this, I will not be champion next year," he added in a definitive 12-word assessment of next year's chances. "It is that simple.
We really have to make steps to be competitive next season. We all know that.
"I trust that the team can fix the balance problems of last season. And certain things that we could not change last year will be changed for next year.
We know that it has to be better over the kerbs, bumps and in the slow corners. Those are generally our weak points. If we are still beaten, it will be on the basis of pure speed."
