A brutal civil war between Liberal Democrats and their Tory coalition partners may be about to erupt in the wake of Deputy Prime Minister Nick Clegg's attempt to draw a thick dividing line between himself and David Cameron over free schools.
It was always understood that the two coalition parties would hold back from the worst assaults on each other's policies until nearer the 2015 general election, with next Autumn's annual conferences the obvious launchpad.
But in the wake of Clegg's surprise announcement that he no longer supports the Tories' free schools policy but wants major reform of the system, a stance which contradicts his own education minister David Laws, it appears the gloves may now come off much sooner.
Senior Tories are seething at what they believe was a calculated ambush, patently designed to placate rebellious left-wing Lib Dems and teachers and appeal to Labour leader Ed Miliband just in case Clegg needs to make a deal with him after the election.
Clegg insists his new policy announcement, to be fleshed out in a speech on Thursday, was simply part of the agreed coalition strategy that the two parties can and should develop distinctive programmes in the run-up to the 2015 poll. It was, he said, an example of "grown-up politics".
But there are plenty of Conservative MPs who believe, far from being grown up, this was "juvenile attention seeking", as one told IBTimes UK.
"Clegg sees his popularity slumping so he is desperate to shore up his support with his own party and has one eye on what might happen if Labour needs to do deals to form a government after the next election," he said.
And, along with other Tories, he believes Cameron and his ministers can no longer sit back and allow Clegg to continue "making up the rules as he goes along" but should go on the offensive.
Some, however, believe Clegg miscalculated this one and was taken aback at the strength of the reaction against his announcement and may have realised he went too far and risked a damaging civil war with his Tory partners.
If that leads to the two sides kicking chunks out of each other now, it would inflict serious electoral damage on both sides, who should be concentrating all their efforts on driving the sluggish economic recovery. But, it is argued, voters will understand when the two parties start mapping out distinctive manifestos in the immediate prelude to the 2015 election.
But there is another problem underlying these inevitable coalition tensions. And it is within the internal Tory coalition, that is the one between Cameron and his "modernisers" and the right-wing and Eurosceptic wings of the party.
The right have never been happy with the idea of coalition with the Liberal Democrats, who they believe are far too left-wing, but fear their leader prefers the Lib Dems to their own brand of Conservatism.
It is widely believed that Cameron is happy to rely on Lib Dem support in government because it allows him to ignore his right-wingers who, he believes, threaten his attempts to reform the party and keep it on the centre ground. As a result, they argue, he gives Clegg plenty of leeway.
In the past, Cameron has described himself as a "Liberal Conservative", much to their irritation.
That takes no account of the fact that Cameron has made significant concessions to his right, notably over a referendum on EU membership, although they write that off, claiming they do not believe the prime minister will deliver.
Some on the right even believe Cameron would prefer to see another Tory-Lib Dem coalition after the next election rather than a narrow Conservative majority, leaving him in hock to their wing of the party.
Even if that can be chalked up to political paranoia - and it would be a hugely dangerous and self-destructive strategy if it was true - it shows the depth of the ill-feeling between the right of the party and the leadership, something Cameron would ignore at his peril and may want to appease.
So the pressure is on. If Clegg continues to spring surprises and appears to be looking for a fight, he may well find he gets one and that could end up hurting both contenders.