It is less the fact of Nick Clegg's decision to veto looser childcare ratios and more the manner of it that has enraged the Conservatives. The Tories are briefing that Clegg signed off on the changes back in January only to reverse his position in order to curry favour with his party. As in the case of the NHS reorganisation and the boundary changes, this was another Lib Dem U-turn.
But on his weekly LBC phone-in show, Call Clegg, the Deputy PM said it was "flatly wrong" to claim that he had ever approved the changes. "What we agreed at the time was that we would consult on these proposals," he said.
"If you have an idea, which is controversial, listen to what the people involved say and then make a decision on it. What's the point of making policy if we don't listen to people it will affect?"
Since the consultation found that most parents' groups thought "this was a bad idea" and that there was "no real evidence" that this would cut childcare costs, Clegg argued that his response was the only appropriate one.
It is one thing for the Tories and the Lib Dems to disagree over policy, as they do in the case of Europe, a mansion tax and the snooper's charter, but that they are now at odds over process, too, shows how dysfunctional the coalition has become.