MONTREAL -- It sounds like an agreement on the Trans-Pacific Partnership is close -- and when it's done, Conservative Leader Stephen Harper says he intends to disclose the details of what he's billing as the largest trade deal in history.

"Progress has been made, but negotiations are still ongoing, and I am receiving regular updates from our officials who are on the ground," Harper told a hastily assembled news conference Saturday morning in Montreal.

"Let me assure everyone that we will only conclude a deal that is in the best interests of our country."

Should the TPP talks taking place in Atlanta indeed conclude with a deal, Harper said the partnership would create thousands of new jobs in Canada and provide access to a market of almost 800 million new customers in the Asia-Pacific region.

It is the government's "intent" to make the details of the agreement public, although the final authority on the deal rests with the Parliament of Canada, which would have to ratify it, he added.

"We need to be at the table to advance and protect our interests, to have any possibility of participating, but the final decision on a deal -- obviously a deal will be made public and the final decision will be voted on eventually by the Parliament of Canada, but we must be there to protect our interests."

He added: "We have a possibility of being in what could be the largest trade deal in history."

The 12-country Pacific Rim trade agreement is far from popular in other circles, however. Dairy farmers in particular in Ontario and Quebec fear Canada is poised to dismantle its supply management system, a regime of production limits and import tariffs that protects domestic producers.

New Democrat Leader Tom Mulcair, looking to shore up what some polls suggest has been flagging support in Quebec, declared Friday that an NDP government would not feel bound by the terms of a deal that he said would be illegitimate if it indeed concludes during the election campaign.

Mulcair and other critics say the government is exceeding its authority during an election campaign -- it is supposed to act solely as a "caretaker" and not take actions that would tie the hands of future governments -- by negotiating an international trade deal.

Later Saturday, Harper was to make his way to an event in the Newfoundland and Labrador riding of Avalon -- his first foray of the campaign into a province that has never shown him much electoral warmth.

Mulcair was scheduled to attend an event in the community of Upton in the eastern townships of Quebec. The community is in the riding of Saint-Hyacinthe-Bagot, one of many that went to the New Democrats in the 2011 orange wave.

In this campaign, however, the NDP's efforts are concentrated on the province that is the party's base of support, and where its numbers have of late shown signs of eroding -- thanks in large measure to the controversy over a Conservative ban on the wearing of the niqab during citizenship ceremonies.

The Conservatives and the Bloc Quebecois support the ban, which is popular in Quebec; the NDP and the Liberals do not.

Bloc Quebecois Leader Gilles Duceppe was to attend a rally in Montreal on Saturday, while Green party Leader Elizabeth May was taking part in a rally in Vancouver.

Liberal Leader Justin Trudeau is off the campaign trail.

However, on Sunday he'll attend what the party has billed as the biggest rally of the campaign, at a hall in Brampton, Ont., that seats up to 5,000 people.