Mercedes has lodged a protest with the FIA over the race classification and a breach of the sporting regulations after a controversial end to the 2021 F1 world championship.
Max Verstappen overtook Lewis Hamilton on the final lap of the Abu Dhabi Grand Prix after confusion under safety car conditions, triggered by a Nicholas Latifi crash, ahead of the last lap.
Race control had instructed backmarkers, five of which were between race leader Hamilton and second-placed Verstappen, would remain in place behind the safety car.
However, after a radio call between race director Michael Masi and Red Bull team principal Christian Horner, the decision was changed to allow backmarkers out of the way of the title fight and un-lap themselves.
This came half a lap before the resumption of the race for the final lap of the season and with Verstappen having pitted for soft tyres during the neutralisation, the Red Bull made light work of the Mercedes with a lunge into turn five.
The only lapped cars able to un-lap themselves were those between Hamilton and Verstappen, with Mercedes deciding to protest the classification.
Red Bull has since made its way to the stewards' office with Mercedes' protest centralised around footage that appears to show Verstappen momentarily ahead of Hamilton during the restart procedure.
A stewards' summons read: "Protest by Mercedes-AMG Petronas F1 Team against the classification established at the end of the Competition, alleged breach of Article 48.12 of the 2021 FIA Formula 1 sporting regulations."
Mercedes has also protested against a breach of Article 48.8, which considers a procedure behind the safety car.
A Mercedes spokesperson said: "We lodged a formal protest within the required 30 minute time window after the end of the race.
"We will not make any further comment on the detail of that until the hearing has been conducted."
What the sporting regulations state
Article 48.12 of the sporting regulations reads: "If the clerk of the course considers it safe to do so, and the message "LAPPED CARS MAY NOW
OVERTAKE" has been sent to all Competitors via the official messaging system, any cars that have been lapped by the leader will be required to pass the cars on the lead lap and the safety car.
"This will only apply to cars that were lapped at the time they crossed the Line at the end of the lap during which they crossed the first Safety Car line for the second time after the safety car was deployed.
"Having overtaken the cars on the lead lap and the safety car these cars should then proceed around the track at an appropriate speed, without overtaking, and make every effort to take up position at the back of the line of cars behind the safety car.
"Whilst they are overtaking, and in order to ensure this may be carried out safely, the cars on the lead lap must always stay on the racing line unless deviating from it is unavoidable.
"Unless the clerk of the course considers the presence of the safety car is still necessary, once the last lapped car has passed the leader the safety car will return to the pits at the end of the following lap.
"If the clerk of the course considers track conditions are unsuitable for overtaking the message "OVERTAKING WILL NOT BE PERMITTED" will be sent to all Competitors via the official messaging system."