Ferrari and Renault are set to push ahead in their appeal against the FIA's punishment of Racing Point in Formula One's 'cheat' storm.
Racing Point were docked 15 points and fined £361,000 for copying parts of the Mercedes Lewis Hamilton last year drove to a sixth world championship.
Ferrari, Renault, McLaren and Williams noted their intention to protest the verdict on the eve of last weekend's 70th Anniversary Grand Prix at Silverstone.
They had until Wednesday morning to decide if they wanted to continue with their action which would involve lawyers at the FIA's Court of Appeal.
The four teams were keen to understand if there could be other parts on the Racing Point machine which are identical to the 2019 Mercedes. It is also understood they do not believe the verdict to be severe enough.
But Ferrari and Renault – the latter's initial protest led to the FIA investigation – will now go it alone, with McLaren saying on Tuesday night: "McLaren Racing has decided not to appeal the decisions of the FIA stewards in relation to Renault's protests of Racing Point.
"The team welcomes the stewards' decisions and findings in this case and importantly that the FIA has demonstrated that transgressions of the rules will be investigated and punished.
"Moreover, McLaren Racing is pleased that the FIA will further clarify the sporting and technical regulations to protect Formula One as a sport where teams are clearly defined as constructors, and removes the potential that the Formula One world championship includes cars that are, in effect, copies of other competitors.
"Additionally, McLaren Racing respects the decisions of Ferrari and Renault to pursue their appeals and will follow proceedings with interest."
Renault tweeted: "We have confirmed our intention to appeal against the stewards' decision in respect of the Racing Point brake ducts. In the meantime, we will continue to work intensively with the FIA and all stakeholders to develop and implement a clear and enforceable regulatory framework that will ensure all teams participating in the 2021 season will develop their original aerodynamic concept by themselves.
Mercedes were dragged into the row after it emerged they had supplied a complete set of 2019 brake ducts to Racing Point on January 6.
It was also established that they provided Racing Point with computer-aided design models for the parts which assisted them in building this year's car, dubbed the 'Pink Mercedes'.
F1's governing body ruled that the transfer of brake ducts from Mercedes to Racing Point did not constitute a "significant breach of the sporting regulations" and the sharing of data was within the rules.
Speaking after last Sunday's race at Silverstone, Mercedes team principal Toto Wolff said: "If someone thinks we have done something wrong then they should protest, and we are happy to go to court.
"Our reputation is very important but it is intact. We have not been protested. We have done nothing wrong."