RIVIERE DU LOUP, Que. -- Liberal Leader Philippe Couillard is warning there would be "serious political consequences" to allowing any further dismantling of Canada's supply management system in order to strike a NAFTA deal.

When asked on the campaign trail today how far he would go to protect supply management, Couillard borrowed a phrase made famous by former prime minister Pierre Elliott Trudeau and answered, "Just watch me."

Couillard told reporters in Riviere-du-Loup that Quebec is opposed to any new concessions when it comes to the system that regulates dairy, eggs and poultry.

The Globe and Mail reported late Tuesday that Ottawa was prepared to make concessions to Washington on Canada's dairy market.

Without mentioning the current Trudeau government directly, Couillard suggested the country's second-largest province will make its disapproval heard if Canada gives in to American demands and grants greater access to its dairy market during tough NAFTA renegotiation talks.

Couillard also reversed an earlier position as he opened the door to co-operating with other political leaders on the issue.

While refusing to participate in a public event with other party leaders in support of supply management, he said today he's willing to sign a document to that effect created by Parti Quebecois Leader Jean-Francois Lisee once he's had the chance to study it.