Quebec Labour Minister David Whissell resigned from cabinet Wednesday. ((Jacques Boissinot/Canadian Press) )

Quebec Labour Minister David Whissell has resigned from cabinet over controversy about his stake in a construction firm.

Whissell, 42, had fended off criticism this week about his co-ownership of ABC Rive-Nord, a asphalting company that does business with the province's Transport Ministry.

ABC Rive-Nord has won about $800,000 in government contracts, many without tenders — including one worth $564,000 for paving work in Whissell's riding.

The member of the national assembly for Argenteuil insists he did nothing wrong under Quebec's government ethics guidelines, but is relinquishing his cabinet post to maintain his holdings in the company.

Allegations of impropriety have hurt his reputation, but he's still proud of his family's long history in the construction business, Whissell told reporters in Quebec City.

Premier Jean Charest stood by Whissell's side during his resignation announcement.

Charest said his former minister's decision has prompted him to review ethics guidelines for cabinet ministers. From now on, anyone who owns a company that deals with the government will not be allowed to sit in cabinet, Charest said.