Merseyside's tram network is firmly on track after city councillors agreed financial backing for the scheme.
The Merseytram scheme has been hit by rising costs
Liverpool City Council has joined Knowsley Council in underwriting a £24m contingency fund for the project.
The fund would be used in the event of the construction of Line One - the first of three proposed routes - running over its £300m budget.
The government will now be asked to release the £170m it pledged towards the scheme in 2002.
"This is a very important day for Liverpool and Merseyside," said Council Leader Mike Storey.
"We have clearly shown our commitment to the tram.
"It is now up to the government to match that commitment and provide the clean transport system the city needs."
In addition to the Department for Transport's £170m, a further £40m will come from Merseytravel and the remainder from Objective One European Social Funding and private sources.
On Thursday, Liverpool entrepreneur Mike McComb revealed he was prepared to offer part of his £70m fortune to ensure the troubled project went ahead.
"There should be no obstacle to this project because I believe its success is vital for the future of this city," said Mr McComb.
Liverpool City Council's executive committee agreed to underwrite the scheme at a meeting on 4 November.