Premier Doug Ford and Canada's largest private sector union issued a joint statement Wednesday calling on the federal government to kick in the cash needed to replace the TTC's aging Line 2 subway trains.

"Thousands of workers in Thunder Bay, where the subway trains are made, and millions of transit riders are depending on the federal government funding its share of the project," Ford and Unifor President Lana Payne said in their statement.

The province has already pledged, as part of its new deal with the city, to spend $758 million to buy the trains, but has made that contingent on the federal government picking up part of the tab as well.

"The province and city reached this deal over seven months ago, but the federal government has yet to announce its commitment," Ford and Payne said.

Less than two weeks ago, outgoing TTC CEO Rick Leary said he's concerned that the TTC is still hundreds of millions of dollars short of the amount needed to replace the trains, which are set to reach the end of their design life in 2026.

“It is very serious. We have seen what happens when you extend the life of vehicles beyond their useful life," Leary said.

Vehicles for the Scarborough RT, which was eventually shuttered following a derailment, were refurbished past the end of their lifecycle because the city had not built a replacement system in time.

The TTC has pegged the cost of buying 55 new trains for Line 2 and 25 new trains to expand capacity on Line 1 at some $3.52 billion.

In a social media post, Mayor Olivia Chow thanked Ford and Payne for their letter.

"Thank you Premier and @UniforTheUnion for your advocacy to secure Federal support for much needed subway cars on the Bloor-Danforth line," Chow wrote on X. "Without it soon, the City will have to use its share of funds to extend our trains past their lifespan, putting reliable service in jeopardy. We need a commitment in the next few months to get the order underway."

In an interview with CP24 Thursday morning, Ontario Transportation Minister Prabmeet Sarkaria said that while new trains are essential to keep Line 2 running, they are also needed as the transit system expands.

"When we talk about Line 2, it's about making sure that the state of good repair of our TTC trains continues to keep up to speed," Sarkaria said. "But on top of that, we've got two new lines coming in that will use these cars; the Scarborough subway extension, the young North Subway Extension, both critical to transit over the next 10 years."

A TTC report back in December warned that the new vehicles are needed to keep the system running properly.

"In the absence of full funding for Line 2 NSTs (new subway trains), the ability to sustain a reliable service on Line 2 is at risk due to the age of the fleet and signalling system," the report said. "Forecasted growth in customer demand on Line 1 will also not be accommodated without a new train procurement advancing."

In a statement, the office of Housing, Infrastructure and Communities Minister Sean Fraser acknowledged that public transit "is essential to building healthy, sustainable, and affordable communities."

Fraser's office pointed out that the federal government is establishing a "Permanent Public Transit Fund," which will provide $3 billion per year to transit projects across the country.

"This commitment that will (sic) create further opportunities for communities like Toronto to make longer-term transit plans, maintain and expand their transit networks, and get projects built," the statement said. "We will have more news to share about the rollout of this fund in the coming weeks."

The statement added that "while we cannot comment on specific funding decisions, we are continuing to collaborate closely with the TTC and the City of Toronto on how we can support their needs."

Transit advocacy group TTC Riders and Environmental Defence also weighed in Wednesday with a statement calling on the Trudeau government to come to the table with funding for the trains, saying that if they don't, "subway service will become less reliable and the TTC will need to spend at least $1.6 billion on overhauling and extending the life of existing trains."

They pointed out that ordering new subway trains "is not like ordering something on Amazon." They said the trains will take years to build and deliver, while the old trains are quickly nearing the end of their expected service life in 2026.

-With files from Chris Fox