A high-speed rail corridor in southern Ontario is "exactly what our economy needs," Premier Kathleen Wynne says.

Wynne officially announced plans for a high-speed rail line from Toronto to Windsor Friday morning, with stops in Kitchener-Waterloo and London, by 2025.

"This is an idea that has been around for a very long time," Wynne said during the announcement in London. "We decided it was time to take a serious look at an idea that's been around for decades."

Wynne said seven million people live along the corridor between Toronto and Windsor and the current transportation options just aren't good enough.

"This is where our economy thrives, is along that corridor," she said. "It's exactly what our economy needs."

The project would use a combination of existing track and new rail lines dedicated to the high-speed train, officials told CBC News. It would include stops in Guelph, Kitchener-Waterloo, London and Chatham, and connect to Toronto Pearson International Airport.

High-speed rail a 'game changer'

London Mayor Matt Brown praised the project, saying it will cut Toronto commute times in half for residents of his city. It's estimated the train would take 73 minutes to get from London to Union Station in Toronto.

High Speed Rail will connect Toronto-Windsor. It will cut the commute between <a href="https://twitter.com/hashtag/LdnOnt?src=hash">#LdnOnt</a> & Toronto in half. <a href="https://t.co/a3XB0Lx5UC">pic.twitter.com/a3XB0Lx5UC</a> —@MayorMattBrown

Kitchener Mayor Berry Vrbanovic, who has been joined by Toronto Mayor John Tory in touting an innovation corridor between the two cities, said he was excited for what high-speed rail will mean for Waterloo region.

"I think this kind of infrastructure announcement, quite frankly, is transformational for the region in terms of becoming a global, technology super-cluster," he told CBC News.

"I think the province recognizes that, if we're going to compete in a global economy, investing in this kind of infrastructure – long overdue in Canada – is an important part of where we need to go."

Having a stop in Guelph "would unlock extraordinary opportunities for our local economy and quality of life," Mayor Cam Guthrie said. And it would "revolutionize" the way residents travel to Toronto, London and Windsor.

Windsor commitment

Windsor Mayor Drew Dilkens said he's pleased to see the project moving forward with environmental assessments.

"I've been on high speed rail all around the world and it really is a game changer," he said. "Knowing that we'd be able to link closer and more intimately with the economic centre of Ontario, the GTA and Kitchener-Waterloo, I think is very good news for the City of Windsor."

But he also expressed concerns about being part of phase two of the project.

"[The] concern that I have on my mind is making sure that we're not excluded, that they don't just stop at London and say okay, we're it, and that's it and we're going to wait for some other government in the future to do it. I think if they're going to make the commitment to build it, it should be from Toronto to Windsor."

This map shows a proposed high-speed rail network in southern Ontario. (Ontario Ministry of Transportation)

'Hollow election promise'?

A number of NDP MPPs from London, Windsor, Essex, Niagara and Kitchener-Waterloo issued a joint statement Friday afternoon saying the promise of high-speed rail may just be "another hollow election promise."

"Premier Wynne may make promises when it comes to our transportation infrastructure, but is always light on action," the statement said.

"Although today's announcement was actually a re-announcement, it could be a step in the right direction and we have high hopes for this environmental assessment, but people in our communities are wondering today whether this is just another hollow election promise."

The MPPs said the province has promised all-day, two-way GO train service between both Niagara and Kitchener-Waterloo, but there's been "no action," the MPPs said.

"Our communities are concerned that this is another case of the premier looking for votes for herself while ignoring the needs of the rest of us," the statement said.

A group called All Aboard St. Marys also criticized the plan, calling it "impractical, unaffordable and unacceptable."

Chris West of the group said any plan that leaves smaller communities such as St. Marys, Stratford, Brantford, Woodstock and Ingersoll "out of the mix is a non-starter."

Phase one: $12 billion

Transportation Minister Steve Del Duca said there will need to be environmental assessments for both the provincial and federal approvals and design work will be done at the same time. That could take up to four years to complete. Construction could begin in four to six years.

The price for phase one of the project – Toronto to London – could be between $4 billion and $12 billion, depending on different factors, Del Duca said, citing a report by Ontario's high-speed rail special adviser David Collenette.

The trains will be 40 to 60 per cent faster than current journey times, but Del Duca said they still need to determine specifics like when trains will run and how much fares will cost.

The goal would be to have phase two, from London to Windsor, completed by 2031.

"We still have a lot of work to do," he said.

Wynne said they plan to get to work "as quickly as we can."

"The cost of the lost opportunity in not doing this is massive. It's billions of dollars of productivity, it's billions of dollars of opportunity and we won't even know how many jobs we could've had, if we had just built this," Wynne said during a second stop in Kitchener Friday afternoon.

"I am absolutely committed to doing this. I know, I know there will be critics. But you know, one of the reasons this hasn't been done up until now is that there have been critics, and there have been people who have said, 'No, no, no, put the brakes on, we're not going to do this.' And so we're not going to let that happen this time."