David Cameron and Nick Clegg are being urged to "call off the dogs" after an escalating row between Tory education secretary Michael Gove and the Liberal Democrats descended into more personal abuse.
Senior Tories and LibDems fear the row, this time over the alleged switching of funds to prop up Gove's "vanity project" of free schools, has become so bitter it is threatening the day-to-day work of the department.
Some reports suggest relations between the education secretary and the deputy prime minister have reached a new low and that in private, they are scathing about each other.
The latest row is between LibDem education minister David Laws and his boss Gove who has been accused of "zealotry" over free schools and ignoring any criticisms.
Tory sources have dismissed the attacks as "pathetic" and an attempt to distract attention away from Clegg's "botched" free school meals initiative.
It was that initiative that saw some of the most personal abuse when Gove's former special adviser, Dominic Cummings, told the Sunday Times that Clegg was "self-obsessed, dishonest and revolting".
The deputy prime minister responded by branding his attacker a "loopy ideologue'".
There are even suggestions that LibDem treasury secretary Danny Alexander is being dragged into the row and is threatening to overrule Gove's departmental budget plans - something he has notably refused to deny.
The party leaders have been urged to order their ministers and, in particular their special advisers, to call off the attacks and focus on the reforming work of the department.
One source said: "This has got out of hand. It's time they called off the dogs. Having a differentiation strategy [between the two coalition parties] is one thing but this is getting silly."
Some believe the prime minister has given Gove, his close ally, a free hand to pitch in against the Liberal Democrats, believing it helped that differentiation strategy in the runup to the general election.
It also plays well with those Tory backbenchers who have always opposed the coalition with the Liberal Democrats and wanted reassuring that Cameron was prepared to crack the whip.
But there is a feeling Gove has taken it to extremes and may even have sanctioned Cummings' outbursts. Whatever the reality, the row has become so personal, even over relatively minor issues, that it is overshadowing what the government believes is its positive message on education.
The row has all the hallmarks of the type of briefings and counter-briefings that used to be routine in the previous Labour government as the Blair and Brown teams kicked chunks out of each other.
Cameron accepted there were "inevitably tensions and pressures" in a coalition.
But, speaking on LBC radio he added: "When you look across the coalition government, what has been remarkable is not that there have been some spats, but what has been remarkable is the amount of good work that has been done to sort out things like education."
The calculation appears to be that sticking it to the Liberal Democrats will pay dividends in election year and that, while some may go over the top, it will do wonders for Tory morale.
And with the normal work of government already taking second place to electioneering, it seems unlikely peace is going to break out any time soon.