One year after the creation of the coalition, Downing Street said the Government had fulfilled a quarter of the commitments it made after last year's election and was "well on the way" to completing two-thirds of its programme.
The claim came as both Conservatives and Liberal Democrats insisted that the coalition remains strong and will survive its five-year term, despite the bruising experience of last week's elections.
Deputy Prime Minister Nick Clegg promised to take a more "muscular" role within Government, as he sought to establish a more distinct voice for his party in response to its mauling by the voters.
He made clear he intends to stay Lib Dem leader up to and beyond the election scheduled for 2015, and insisted that his party will be able to be more assertive in Government without undermining the stability of the coalition.
But a YouGov survey of more than 500 current and former Lib Dem members for Channel 4 News found that more than half (52%) think the coalition will collapse before 2015, and more than one-third (35%) do not want Mr Clegg to lead them into the next election.
In a speech to mark the coalition's anniversary, Mr Clegg accepted his party had been given a "bloody nose" by voters, and said the Government must change the way it operates.
"In the next phase of the coalition, both partners will be able to be clearer in their identities, but equally clear about the need to support Government and government policy," said the Deputy Prime Minister. "We will stand together, but not so closely that we stand in each other's shadow.
"You will see a strong liberal identity in a strong coalition Government. You might even call it muscular liberalism."
The anniversary came on a day of difficult news for the Government, with the Bank of England downgrading growth forecasts and predicting higher inflation until at least 2013, while disabled people marched past Parliament to protest at welfare cuts.
But Prime Minister David Cameron insisted that the coalition had "a record to be proud of" after its first 12 months in Government.