MONTREAL - Add Lucien Bouchard's voice to all those clamouring for a public inquiry into allegations of corruption in Quebec's construction industry.

The former Quebec premier said he was originally opposed to such a probe because of the dangers of incriminating people during televised proceedings.

But Bouchard has changed his tune, saying Premier Jean Charest's government is paying a heavy political price for its steadfast refusal to hold a public inquiry.

And in a rare interview since he quit politics a decade ago, Bouchard told Radio-Canada on Thursday night that such a probe would help improve Quebecers' perceptions of government and the political process.

Charest has refused to call an inquiry into widespread allegations of collusion and corruption involving some construction companies, union officials and criminal groups such as the Mafia.

Charest has set up special police units to target alleged wrongdoers but convictions have been in short supply.

His refusal to bow to the constant demands for an inquiry is widely viewed as one of the main reasons his Liberal government has been slumping in opinion polls for months.

Bouchard's interview also focused on his new role as head of the Quebec Oil and Gas Association.

His new job will see Bouchard promoting the use of shale gas in the province at a time when the industry has fuelled considerable environmental concerns.

Bouchard said it is important for the industry to thrive while at the same time respecting environmental guidelines.