Former world champion Jacques Villeneuve has accused Lewis Hamilton of being too aggressive in his driving at the start of Grands Prix.
Villeneuve believes Hamilton has not yet proved himself
The Canadian said Hamilton's behaviour was similar to that of former champion Michael Schumacher, who was widely criticised for dirty driving.
"When will these chopping moves stop?" Villeneuve told Autosport magazine.
"Lewis is not getting penalised and his behaviour off the start has started to look the way Michael used to."
Hamilton has begun his Formula One career with greater success than any driver in history, and his ability to make places off the start is one of many ways in which the 22-year-old has attracted attention.
But Villeneuve said he was surprised race officials had not waved a black flag at Hamilton, calling him into the pits for potential disqualification for dangerous driving.
Lewis is very fast but he still has to step up to the plate and beat Alonso
"So far, he has been lucky, so we'll see if it carries on," said Villeneuve, who won the title for Williams-Renault in 1997 and whose F1 career ended last season.
"He makes progressive moves that would have got some of the other drivers black-flagged."
Hamilton heads into this weekend's Canadian Grand Prix tied on points at the head of the world championship with team-mate and double world champion Fernando Alonso.
And he has been faster than the Spaniard in the last three races, beating Alonso in Bahrain and Spain but being asked by the team not to challenge him for victory in Monaco.
But Villeneuve believes Hamilton still has some way to go before he has fully established himself as a leading contender.
Hamilton's moves at the start are unfair, Villeneuve believes
"Lewis is very fast," Villeneuve said, "but he still has to step up to the plate and beat Alonso.
"And we still haven't seen how he reacts under pressure - that will be interesting to watch."
Villeneuve's remarks are the first time Hamilton has faced any public criticism since the start of his F1 career this season.
Follow the Canadian Grand Prix live on the BBC Sport website and Radio Five Live. Qualifying is at 1800 BST on 9 June, with the race 24 hours later.