The accusations are made in a new book entitled Syndicalistes ou voyous? — Unionists or Thugs? in English — written by former top union officials, Jocelyn Dupuis and Richard Goyette.
The book claims Coderre arranged a secret meeting with the union officials during the 2000 federal election campaign, when he was a Liberal cabinet minister.
Dupuis, a former head of the Quebec Federation of Labour's powerful construction arm, said he received a phone call from Eddy Brandone, a union official who has since been linked to well-known mafia figures.
"He called me in the middle of the night for a meeting at a restaurant," said Dupuis.
Dupuis said Brandone invited him to meet with two federal cabinet ministers: Alfonso Gagliano and Coderre.
According to Dupuis, the two men promised to consider the Quebec Federation of Labour's claims in a controversial bill to change the Employment Insurance program.
In exchange, Gagliano and Coderre asked him to cancel a demonstration planned by workers in the constituency of then Prime Minister, Jean Chrétien.
The demonstration was called down, but Dupuis said Coderre and Gagliano never kept up their end of the bargain.
Coderre doesn't deny the meeting took place, and he doesn't deny Brandone set it up, but said there was no secret deal.
"There has never been a secret agreement," said Coderre.
Coderre said all he and Gagliano promised to do was try their best to help the unions, but the leaders were never satisfied.
Coderre said he believes Dupuis is bitter and now trying to improve his own tarnished reputation by lashing out at others.
Dupuis is currently facing fraud charges related to expense claims.
Syndicalistes ou voyous? is set to be published later this week.