Trudeau says feds 'on it' as Canada's biggest railways grind to a halt ...

Canada's two biggest railways have ground to an unprecedented halt, and as pressure mounts for federal intervention, Prime Minister Justin Trudeau says his government will have more to say "shortly" on what it is doing "to make sure that the right solution is found quickly for the economy."

"We're taking it so seriously. The minister is engaged directly. We are not taking this lightly, obviously, because Canadians across the country are worried about it," Trudeau said Thursday in Sherbrooke, Que. in front of a manufacturer that will be impacted if the shutdown continues much longer.

"That's something that is an impact right across the country, from workers, to businesses, to farmers, to consumers, who are going to be impacted. That's why we are on this," Trudeau said.

Unable to reach a deal, the Canadian National Railway (CN) and Canadian Pacific Kansas City (CPKC) locked out their workers early Thursday morning in a first-ever simultaneous work stoppage. The Teamsters Canada Rail Conference has issued a strike notice at CPKC but not at CN.

In a statement Thursday morning, CN said that "without an agreement or binding arbitration, CN has no choice but to finalize a safe and orderly shutdown and proceed with a lockout." 

The union, meanwhile, said that after months of "good-faith negotiations," safety-related issues remain its focus.

"Neither CN nor CPKC has relented on their push to weaken protections around rest periods and scheduling, increasing the risk of fatigue-related safety issues," Teamsters Canada's statement reads.

"CN also continues to demand a forced relocation scheme, which could see workers ordered to move across the country, tearing families apart in the process."

Speaking to reporters earlier, Public Services and Procurement Minister Jean-Yves Duclos said the fastest way to get workers back to work, is through a negotiated agreement.

"That is also the best possible outcome for the appropriate relationship that needs to take place over the years between the unions and the two businesses," Duclos said.

According to the Railway Association of Canada, the critical transport lines impacted by the shutdown carry more than $1 billion worth of goods each day.

More than 32,000 rail commuters in Toronto, Montreal and Vancouver are also affected, as regional transit authorities have select commuter lines that run on CPKC tracks.

Contract talks are ongoing Thursday in Montreal and Calgary, as picket lines go up. 

Labour Minister Steven MacKinnon's office says he continues to follow the matter closely and is "in meetings all day on this extremely important situation." Late last night, MacKinnon – who is just over a month into his cabinet portfolio – told CTV News that the issues between the two sides "remained significant."

"It's a heck of a situation for the government right now, but there are tools in the government toolbox, and they're going to have to start using them," said former NDP leader Tom Mulcair on CTV News Channel. "Because obviously this can't continue for very long." 

Criticized for not acting to prevent the shutdown, there are ongoing calls from big business groups and impacted industries for the federal government to step in, either through enacting labour code provisions referring the dispute to the Canada Industrial Relations Board for binding arbitration, or back-to-work legislation.

Back-to-work-legislation would require the federal government to recall Parliament, which is currently on a summer break until mid-September. The minority Liberals would also have to secure support for the legislation from another political party, a prospect that right now is uncertain.

NDP Leader Jagmeet Singh reiterated Thursday his party's longstanding opposition to back-to-work legislation.

Appearing alongside some of the more than 9,000 engineers, conductors and yard workers, Singh said he doesn't want to see any federal interference. In his view, Trudeau would be rewarding the "bad behaviour" of "the big bosses."

"They know we will not support any interference, not just back-to-work legislation,” Singh said. “If it comes to Parliament, we will be voting against it. We will oppose it. We will make it very clear we're the only ones, the only party that will always stand in solidarity with working people."

"We should always negotiate fairly, put pressure on getting a fairly-negotiated solution, but never force the workers back."

Bloc Quebecois Leader Yves-Francois Blanchet told CTV News ahead of the lockout that he did not support federal intervention yet, but he did not rule out that possibility in the future depending on the impacts.

Conservative Leader Pierre Poilievre, who is trying to court working-class voters – and backed the Liberals' recent anti-scab law – has yet to respond to requests for comment. 

Former Conservative labour minister Lisa Raitt said when it comes to the Conservative's position, it is not yet on them to offer anything up, until the federal government moves.

She predicts Poilievre will land on backing back-to-work legislation, given the expected feedback his MPs will hear from their farming and freighting constituents who are being negatively impacted by the stoppage.

"Eventually Mr. Poilievre is going to say something. I just don't think he needs to say it 12 hours after a work stoppage has commenced," Raitt said.

She said the federal government already has "all the key factors" it needs to make a judgement on whether it will issue back-to-work legislation, from the economic input to the appearance of an impasse between the negotiating parties.

"Knowing those two things, knowing the impact on the national economy, and knowing that a recent court ruling has said very clearly that, while it is an infringement on the Charter rights of the union to order back-to-work legislation, it can be justified in certain cases," Raitt said.

"And as a result, the federal government should take a look at that, because I can't think of a more clear case of economic harm to the national economy than the one we're experiencing right now."

Raitt said another option the government has, is to try to get the parties to agree to cool off their work stoppage and start it back up again in September once Parliament is back in session.

"I do think that the union and the companies should be mindful of when the government can actually pull their levers to bring people back… in an amount of time that is, at least, less harmful," she said. 

This is a developing story, check back for updates…