Premier Dalton McGuinty is tripling the province's contribution to help fund a $2.1-billion transit expansion that will bring light rail and a downtown tunnel to Ottawa.

McGuinty is pledging $600 million in funding to be used specifically for transit over the next eight to 10 years. He is urging the federal government to match the contribution.

The first phase of Ottawa's master plan for transit was originally pegged at $1.4 billion; then it climbed to $1.8 billion. Now, the total cost for phase one is estimated at $2.1 billion.

The province had previously committed $200 million in funding for the project. McGuinty announced the additional $400 million on Wednesday.

The premier also made it clear there won't be any more provincial money for Ottawa transit.

The provincial funding is the largest single investment Ontario has ever given to the City of Ottawa.

"This is a game changer for the City of Ottawa," said Mayor Larry O'Brien. "This makes life easier for you, the citizens."

The announcement comes as the province tries to find ways to tackle its $24.7-billion deficit.

The government is currently considering a funding freeze for hospitals, and is looking at selling some of Ontario's most valuable assets: the LCBO, OLG Corp., Hydro One Inc. and Ontario Power Generation.

So far, the federal government has committed $200 million in funding for Ottawa's transit plan.

A spokesperson for federal Transport Minister John Baird said the government is reviewing Ottawa's vision for transit and will be able to say more about federal funding in the new year.

A city transit committee approved phase one of the project on Wednesday. City council is expected to make a final decision on the project on Jan. 13.

With a report from CTV Ottawa's Kate Eggins