Former Formula 1 world champion Nigel Mansell believes McLaren will find it "tough" to go up against Red Bull and the works Renault team with the same engines in 2018.
Mansell, speaking in an interview with Motorsport.tv at Autosport International, hopes Renault is fair in its supply and does not favour one team over the others.
"It's going to be tough, but hopefully they will be able to get very close and hopefully Renault will be very fair with the supplying of engines," said Mansell.
"Obviously, Mercedes don't want to supply them because they don't want them as competitors. The hardest thing in F1 is to get a level playing field.
"We need a better level playing field, we need 26 cars on the grid and we need not to be able to spend fortunes to try and bend the regulations."
Mansell also reflects on his rivalry with Ayrton Senna, the spectacle of Autosport International and his golfing prowess.