The leader of the federal NDP is calling on the Trudeau government to withhold its signature from the new North American free trade deal while American steel and aluminum tariffs remain in place on Canadian exports.​

Jagmeet Singh took a stance similar to one articulated Friday by a senior Mexican trade official, Juan Carlos Baker, who said that a solution to the U.S. "national security" tariffs must be found before the new U.S.–Mexico–Canada Agreement (USMCA) is signed. That signing ceremony is planned for Nov. 29 or 30, before the Mexican government changes hands.

"We're calling on the government to only sign the USMCA if the illegal trade tariffs are lifted once and for all," Singh said in the foyer of the House of Commons Monday.

Tariffs undermine thousands of well-paid jobs, Singh said — and once those jobs are lost, "they won't come back."

As Singh spoke, he was flanked by steelworkers — including Marty Warren, a director with the United Steelworkers union from southwestern Ontario.

"Don't fall into Trump's games. Because you know where he's going with this," Warren said, warning that a U.S. demand to limit Canadian steel exports through quotas would be next.

"There is no need for tariffs or quotas in this integrated steel market," Warren said. "[Canadian workers] are not the problem."

The Trump administration imposed a 25 per cent tariff on foreign steel imports and a 10 per cent tariff on on foreign aluminum products last spring, citing the need to protect its domestic steel industry on "national security" grounds. Allies such as Canada were exempt from the tariffs at first.

A few months later, the Americans announced that Canada, Mexico and the European Union also would face the tariffs. The Trump administration's justification for the tax also began to shift: senior officials started talking about the tariffs serving as excellent negotiating leverage in the talks to update the North American Free Trade Agreement.

Those negotiations concluded and text of the new agreement was released at the start of this month. But the steel and aluminum tariffs remain in place.

Work continues to end tariffs: PM

American and Canadian officials have said that talks to end the tariffs are on a "separate track" from NAFTA's renegotiation.

Foreign Affairs Minister Chrystia Freeland has appeared to rule out accepting quotas on Canadian steel exports as a compromise to get the tariffs lifted.

Mexican officials have not explicitly ruled out quotas. Mexico agreed to quotas for its automotive industry in order to dodge the threat of future automobile tariffs from the U.S.

Prime Minister Justin Trudeau, seen here touring the Essar Steel Algoma plant in Sault Ste. Marie, Ont. earlier this year, says his government continues to work on restoring Canada's exemption from U.S. steel and aluminum tariffs. (Justin Tang/Canadian Press)

Reporters asked Prime Minister Justin Trudeau on his way into question period today whether Canada would hold back from signing the USMCA if a tariff solution remains elusive.

"We're going to continue to work to ensure that the U.S. lifts its unfair steel and aluminum tariffs," Trudeau said. "While we look forward to that day so we can lift our counter-measures as well, we're going to continue to work with the U.S. because this is something that matters to us and, as I've said, I'm always going to speak up for our steel workers."

Baker said Friday that no formal negotiations had taken place on lifting the tariffs, although Mexico has had some exchanges with the U.S. on the issue.

Meanwhile, an American official at the World Trade Organization in Geneva said that the U.S. had held "constructive discussions on the tariffs with Canada and Mexico" and was "hopeful these discussions may be concluded satisfactorily," according to a report from Reuters.

Seven different cases have been brought to the WTO over the U.S. national security tariffs. The U.S. also has fired back with objections to the retaliatory tariffs imposed by Canada and others, arguing that this tit-for-tat move was against international trade rules.

Watch the Power Panel discuss calls to not sign the USMCA below