A former member of Montreal's executive committee offered damning testimony Tuesday against his former colleagues accused in the Contrecoeur scandal.

Former city of Montreal executive committee chair Frank Zampino and five others are on trial for fraud, abuse of trust, and conspiracy.

Benoit Labonté was once a high-profile member of Mayor Gerald Tremblay's team. Elected in 2005 as part of Union Montreal, he was the mayor for the Ville Marie borough and part of the executive committee, the municipal equivalent of a provincial or federal cabinet.

But following a falling-out with mayor Tremblay, Labonté became the leader of the Vision Montreal opposition party.

He ultimately left politics in disgrace in 2009 after admitting to accepting $100,000 in campaign donations from Tony Accurso -- a practice that at the time was entirely legal.

Appearing in court Tuesday via videoconference from the Philippines, Labonté said the same thing he did in 2009: that corruption was endemic at Montreal City Hall.

He said that Bernard Trepanier, aka Mr. Three Percent, was a fundraiser who was frequently seen at City Hall with Sammy Forcillo and Zampino, and even had a city-hall-issued business card.

Labonté said he felt that party fundaisers should not be mixing with administrators at city hall.

Tremblay, who has said in the past that he knew about kickbacks at City Hall as far back as 2001, testified on Monday and is scheduled to continue being cross-examined on Tuesday afternoon.