McLaren are set to confirm they have reached an agreement with Renault, which will see the French company provide its engines to the Woking-based team from next season.
Renault will replace Honda engines, which have proved to be extremely fragile since the Japanese giant returned to the sport in 2015. It reportedly contributes as much as $100m to McLaren's budget.
The F1 racing outfit have been in negotiations with Renault for months, after the team's executive director Zak Brown admitted patience was wearing thin and hinted the team could end its partnership with Honda and the duo have now reached an agreement.
According to the Daily Mail, McLaren will confirm Renault as its engine supplier before this weekend's Singapore Grand Prix when they will also announce Fernando Alonso will sign a new deal with the team.
The Spaniard, whose contract with McLaren expires at the end of the current season, has been linked with a host of teams ahead throughout the summer and was expected to make a decision by the end of September after revealing he has had a number of offers.
The 36-year-old was forced to retire in the Italian Grand Prix two weeks ago (3 September). He has picked up a meagre 10 points so far this season and has not finished any higher than fifth since returning to McLaren in 2015.
The Spaniard had reportedly lost patience with Honda's travails and had made it clear to McLaren that his decision on whether to extend his deal with the team would be contingent on it securing a new engine manufacturer.
According to the Mail, the terms of Alonso's new contract are in line with his current deal, which sees him earn just over £20m a year.
While the double announcement is expected to be seen as a major boost for the team and for the sport as a whole, former Formula 1 supremo Bernie Ecclestone has questioned the wisdom of switching engine supplier.
"The Renault deal is all done [and] Alonso staying is super news," he was quoted as saying.
"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."
Meanwhile, it is understood Honda will supply Toro Rosso from next season. Last week, it emerged that F1 executives were hoping to keep the Japanese giant in the sport even if McLaren were to walk away.
Renault had made clear it would work with McLaren only if they dropped the Italian team as they can not provide engines to more than three teams – Renault, Red Bull and Toro Rosso currently all run Renault engines – for fear of reliability issues.
It now appears a deal has been agreed, which will see Honda remain in F1 and supply Toro Rosso instead.