Red Bull are set to split with engine partner Renault at the end of the 2018 Formula 1 season, multiple sources have told BBC Sport.
Renault have told Red Bull they no longer want to supply them after next season and while the move has not been officially confirmed, insiders say the divorce is almost certain.
Red Bull will be forced to use Honda engines with both its teams in 2019.
Junior team Toro Rosso’s switch to Honda is to be confirmed on Friday.
McLaren’s switch from Honda engines to Renault for the next three seasons, the same period as Toro Rosso’s Honda contract, is also due to be announced on Friday as part of a busy series of news developments at the Singapore Grand Prix weekend.
Source: BBC Sport