Ontario Premier Kathleen Wynne stressed the need for an ‘honest conversation’ about paying for transit expansion throughout the GTA as government officials celebrated a milestone in the $2.6 billion Spadina-York subway extension.

The 8.6-kilometre extension is currently under construction and will stretch from Downsview Station to Vaughan Metropolitan Centre, marking the first time Toronto Transit Commission services extend outside of Toronto’s borders. A total of six new subway stations will be built.

“We’re excited because we’re connecting communities for Ontarians,” Wynne said during a press conference at the future Highway 407 Station site on Wednesday morning.

Wynne was joined by federal officials, TTC Chair Karen Stintz, Toronto Mayor Rob Ford and Vaughan Mayor Maurizio Bevilacqua.

TTC CEO Andy Byford told CP24 he is looking forward to seeing the extension open.

“This is literally ground-breaking,” Byford said. “I cannot wait to get this line open.”

Funding for the extension is being split between the City of Toronto, York Region and the provincial and federal governments, but Wynne said it’s time for new ideas on how to foot the bill.

“We have to have an honest conversation about how we’re going to pay for transit going forward, because the needs are huge and we cannot afford to take a long break,” Wynne said.

The City of Toronto is kicking in $526 million for the extension and York Region is providing $352 million. The province will be providing $870 million in funding and the federal government will be contributing $697 million.

Meanwhile Ford said the extension will benefit the city by reducing congestion, creating jobs and improving productivity for GTA businesses.

“We’re truly creating rapid transit in this city and beyond,” Ford told reporters at the event.

Ford has been very vocal about his desire to build subways in Toronto and his opposition to new light rail transit projects.

The Highway 407 site will be the second last stop of the six new stations on the Toronto-York-Spadina subway extension.

New stations are also being constructed at York University and the yet-to-be-built Vaughan Metropolitan Centre, which will define the city’s 'new' downtown.

The megaproject has already suffered serious setbacks. In 2011, work at the York University station was shut down for several months after a crane operator was killed on the construction site.

TTC officials later said the death delayed the opening of the line’s new stations by about a year.

Service isn’t expected to begin on the Spadina extension until at least fall 2016.