Jacques Villeneuve has criticised Fernando Alonso's decision to join McLaren Honda, claiming that the Spaniard has ruined his chances of another Formula 1 drivers' title.
Alonso quit Ferrari after five seasons with the Scuderia to rejoin McLaren, but has found himself languishing towards the back of the grid in the early part of the season.
However, Villeneuve has suggested that Alonso's decision could have effectively ended his hopes of competing for championships.
He told AS: "Leaving Ferrari was clearly a mistake. He could have spent three or four more years with them and then retired or gone to McLaren if he wanted to win with them as he did in 2007.
"I think Alonso would have fought for the title with this Ferrari.
"With this move. Alonso may have ended his career. He may not win any more titles or even races."
McLaren are one of two teams yet to score a point this season.