Simmering tensions within the coalition boiled over as senior Conservative and Liberal Democrat figures were involved in a series of highly public clashes.
David Cameron faced calls to stamp his authority on his junior coalition partners as divisions over reforms of the NHS, employment and House of Lords reform erupted into the open.
Former defence secretary Liam Fox put himself at the head of Tory MPs demanding a greater say over Government policy, reminding the Prime Minister that they accounted for "five sixths of the coalition, not half".
Lib Dem deputy leader Simon Hughes responded with a warning that the party's peers would seek to re-write key elements of Health Secretary Andrew Lansley's NHS reforms when the Health and Social Care Bill returns to the Lords this week.
Meanwhile, senior Lib Dem Lord Oakeshott warned the party would wreck Conservative plans to re-draw the parliamentary boundaries if Tories blocked Deputy Prime Minister Nick Clegg's proposals for an elected House of Lords.
In an angry on-air spat with a Conservative backbencher, the peer denounced Tory MPs as "headbangers" and accused them of adopting "wrecking tactics". The public display of feuding will fuel speculation over whether the coalition can survive to May 2015 as Mr Cameron and Mr Clegg had originally agreed.
On a fractious day, the initial shots were fired by Dr Fox who used his first major television interview since his resignation last year to challenge Mr Cameron to overrule the Lib Dems and push through changes to the labour laws making it easier for employers to hire and fire staff.
"The objections inside government and outside government - but, yes, including some of the arguments put forward by our coalition partners - they need to be taken on and overridden otherwise we become about managed decline for Britain," he told BBC1's Sunday Politics.
In the same studio, Lord Oakeshott then became involved in a furious row with Tory right-winger Philip Davies over Lords reform, warning him that the Conservatives would be fighting the next general election on the old parliamentary boundaries if the changes to the upper chamber did not go through.
"I think we will not be wanting to put that through if they welch on the other half of the deal. No, a deal's a deal," he said. Mr Davies responded by accusing the peer of making "petulant" threats, and challenging the Lib Dems "to run away from the coalition" and fight an election.