A motion of no confidence in Rishi Sunak's Government will be tabled after the Tories suffered crushing losses in last week's local elections.
The devastating results show the public has no faith in the under-fire PM and his ministers, the Lib Dems say.
Leader Sir Ed Davey, buoyed after his party took control of 12 councils and gained an extra 407 seats following Thursday's vote, is set to table the motion as soon as Parliament returns.
He urged the Tories to accept their time is up, calling for a General Election.
The Conservatives are licking their wounds after shedding 1,061 councillors, with Labour, the Lib Dems and the Green Party among the main beneficiaries.
Sir Ed said: “Time’s up for Rishi Sunak and his out-of-touch Conservative Government.
“The local elections showed that the public clearly has no confidence in Sunak or the Conservatives, so it’s time for a general election now.
“There’s only one reason Rishi Sunak would deny British people a say at the ballot box: because he is running scared and knows he’d lose.
“It’s time for these out-of-touch Conservatives to face the music for their appalling failures on the cost of living, the NHS, sewage and so much more.”
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The Lib Dems took control of 'Blue Wall' authorities in Windsor and Maidenhead, Stratford-on-Avon and Surrey Heath.
Meanwhile Labour's big wins included victory in target areas Medway and Swindon.
The Lib Dem draft motion reads: “That this House has no confidence in His Majesty's Government.”
A Tory spokeswoman said: "This just shows the Lib Dems are more interested in playing political games than addressing the issues facing the nation.
"Meanwhile, the Prime Minister is focused on delivering on his five priorities.
"Only the Conservatives can be trusted to put the British public first."
If a Government were to lose a vote, Mr Sunak would be expected to ask the King to dissolve Parliament, triggering a General Election.
This last happened in 1979 under Labour's James Callaghan.
However, it is unlikely a vote will be held as the government only has to make time for one if it is tabled by the official Opposition party.
If a vote did take place, it is expected the government would win comfortably because the Conservatives have a majority.
The PM will face tough questions from within his own camp after the election results.
Ex-Levelling Up Secretary Simon Clarke said the party was punished for abandoning housing targets - which he branded a "major mistake".
Mr Sunak caved in to demands from Tory rebels and abandoned mandatory housebuilding targets last year, despite huge demand for new homes. Last week he was accused by Labour of "killing the dream of homeownership for a generation".
This, and the chaos unleashed by Boris Johnson and Liz Truss last year, was behind the election drubbing which saw the Conservatives shed over 1,000 council seats, Mr Clarke said.
The senior Conservative told BBC Radio 4's Today: "In these results there is one theme that stands out above all others for me is that we cannot out-nimby the Liberal Democrats and the Greens, so one aspect of policy that does need to change and change as a matter of urgency is our housing policy.
"So we can get back to building the homes that people need, making the case - the moral, economic, political case - for building the homes that a growing population requires rather than, I'm afraid, trying to pander to the public's worst instincts on this question, which isn't working. I would say that dropping those targets was a major mistake and I would like those restored."
