McLaren will usher in a new era this week by announcing that Fernando Alonso will re-sign and their cars will be powered by Renault next season.
After months of negotiations, the landmark news will be confirmed in Singapore, ahead of this weekend's night race around the city-state's illuminated streets.
Sportsmail understands that subject to any unexpected late hitch, the new bosses of Britain's most successful Formula One team have pulled off the double success by agreeing to ditch their current partners Honda, whose engines were woefully underpowered and grossly unreliable.
Changing engine suppliers is everything that Alonso hoped for. He had made being able to drive a competitive car next season the key factor in deciding whether to carry on at McLaren, and possibly even Formula One itself.
Retaining the double world champion Spaniard is a major boost for the sport, as well as for Alonso's bank balance. The terms of his new contract are believed to be similar to his existing package, just north of £20million annually.
Bernie Ecclestone, Formula One's chairman emeritus, said: 'The Renault deal is all done. Alonso staying is super news.
'But I can't see why McLaren will be any happier with Renault than they are with Honda. It wasn't Honda's fault things didn't work out, it was McLaren's. Every day they had a fight about everything, instead of working with them, which was a little bit stupid.'
Nonetheless, McLaren will trumpet the news loudly, believing the developments are the most important of the team's post-Ron Dennis era.
Executive director Zak Brown has played a key part in the Alonso-Renault negotiations under the direction of the team's executive board.
In other parts of the jigsaw, Spaniard Carlos Sainz, 23, is set to leave Toro Rosso to join the Renault works team for the next-but-one race in Malaysia, casting doubt over the future of Britain's Jolyon Palmer. Honda will then power Toro Rosso next season.