OTTAWA –Political figures on both sides of the Canada-U.S. border are coming to the federal government's defence amid ongoing attacks from U.S. President Donald Trump, who has taken to Twitter several times over the last few days to insult Prime Minister Justin Trudeau and make threats about more tariffs.

The issue was the first topic discussed during the first question period since Trump and insiders took to social media and major American television networks to dole out public scorn at Canada.

"While Canadians stand together, President Trump stands alone. American lawmakers and U.S. allies strongly oppose Trump's erratic behaviour against their biggest and closest friend," said NDP House Leader Ruth Ellen Brosseau.

Longtime Liberal MP and cabinet minister Dominic LeBlanc led question period for the government side, with the main ministers who attended the G7 summit not present in the House of Commons.

Fielding questions from the opposition about finding collective solutions to respond to Trump and both planned and floated tariffs from the U.S. administration, LeBlanc thanked the opposition parties for their backing.

"We will always stand for Canadian workers and thank our colleagues opposite for their support," said LeBlanc. "We will also work with all members of this House to ensure that the response that our government takes to these unjustified and unreasonable tariffs is measured and proportionate."

Following question period, the House of Commons unanimously agreed to a motion presented by NDP MP Tracey Ramsey, condemning the U.S. actions given the "longstanding, mutually-beneficial trading relationship."

The motion has no real teeth, but offers a collective parliamentary backing of the Canadian steel, aluminum, and supply management sectors and support for the Canadian government’s retaliatory tariffs.

It also and states that MPs "reject disparaging ad-hominem statements by U.S. officials, which do a disservice to bilateral relations and work against efforts to resolve this trade dispute."

Ottawa has planned dollar-for-dollar retaliation on the U.S. imposition of steel and aluminum tariffs on Canada. These countermeasures amount up to $16.6 billion in imports of steel, aluminum, and other products from the Unites States, and are set to come into effect July 1. The window for public consultation on expanding or pairing down the final list of products ends this Friday.

The Trump administration’s condemnation stems from Trudeau’s assertion that Canadians "are polite, we're reasonable, but we also will not be pushed around."

He made this comment at the end of the G7 summit during a news conference on Saturday. Not long after Trump issued two tweets calling Trudeau "very dishonest & weak."

White House trade adviser Peter Navarro told Fox News on Sunday that Trudeau "deserves a special place in hell" for trying to "stab (Trump) in the back on the way out the door," after Trump left the G7 in La Malbaie, Que., and pulled his nation's support for the joint communique.

‘They strung Canadians along’

On Monday, former U.S. Ambassador to Canada Bruce Heyman called on Navarro to formally and publicly apologize.

“This man should apologize not only to the prime minister but to the Canadian people,” Heyman told CTV’s Power Play.

Heyman, a Barack Obama appointee, added that he believes Trump’s behaviour at the G7 summit is all part of a larger strategy to scuttle NAFTA negotiations.

“I don’t think they want NAFTA. I don’t think they ever really did,” he said. “I think they strung Canadians and Mexicans along with this.”

The former ambassador added that he believes the trade fight is causing Republican senators and governors who depend on the trade agreement to finally break ranks with the president.

“I was always wondering where it would be that the Republicans would start dividing (into) the Trump Republicans (and) what I consider the core global Republicans that I’ve known for so long,” he said.

“I think we’re starting to see a break here.”

Canadian leaders, U.S. Senators speak up

Over the weekend, both Conservative Leader Andrew Scheer and NDP Leader Jagmeet Singh tweeted their support for the federal Liberals, after Trump's tweets about Trudeau.

"Divisive rhetoric and personal attacks from the US administration are clearly unhelpful," Scheer said.

Singh echoed this, chalking Trump’s approach up to "bully tactics."

MPs speaking to The Canadian Press said they've heard from constituents who are worried about the implications of Trump's assertions, and it's expected the weekend's war of words will be a focus during question period on Monday afternoon.

On Sunday, Republican Maine Sen. Susan Collins took to Twitter, highlighting how many border communities are "truly intertwined," and how it’s a friendship that "must" be preserved.

Sharing a Politico article about Navarro’s comments, Republican Arizona Sen. Jeff Flake issued a call-out to fellow party members, saying "this is not who we are."

Speaking to the U.S. levelling of tariffs on Canada and other allies, Flake spoke in the U.S. Senate recently, denouncing the president’s protectionist trade position.

On Sunday, responding to the messaging from the U.S. administration, Foreign Affairs Minister Chrystia Freeland said Canada "does not believe that ad hominem attacks are a particularly appropriate or useful way to conduct our relations with other countries."

Americans are also using the hashtags #ThankCanada and #ThanksCanada to post positive comments about what Canada has done, from hockey to poutine.

Freeland, Lighthizer keep tweets out of trade talk

After a rocky G7 summit, Freeland had a lengthy conversation with U.S. Trade Ambassador Robert Lighthizer Sunday evening, but the series of tweets were not on the agenda, according to a senior government official.

"Tariffs, not tweets" were discussed, according to the official, who spoke on the condition of anonymity.

Instead, the two discussed the stalled North American Free Trade Agreement negotiations, as well as the exchange of steel and aluminum tariffs.

The U.S. Chamber of Commerce rang the alarm Monday about the potential for hundreds of thousands of job losses as the result of Trump’s tariffs, and what could be over a million more if the Americans pull out of the NAFTA deal.

Upping the ante from South of the border https://t.co/CdGwXR1hpw — Mercedes Stephenson (@CTVMercedes) June 11, 2018

Today as the former US Ambassor to Canada I am calling on Peter Navarro to formally and publicly apologize to @JustinTrudeau and more importantly the Canadian people for his insulting and inappropriate remarks on @FoxNewsSunday https://t.co/25tzXMHUgf — Bruce A. Heyman (@BruceAHeyman) June 11, 2018

We’ve had differences w/ Canada over the years, particularly regarding subsidies from the provincial & nat’l governments; nevertheless, Canada remains our close ally, good friend, & one of America’s biggest trading partners. In Maine, we have a special relationship w/ Canada. 1/2 — Sen. Susan Collins (@SenatorCollins) June 10, 2018

With files from CTV News Channel’s Michel Boyer, and The Canadian Press