When Labour retreated, it sewed several landmines in the political territory it was about to cede. One of them was Harman's Equalities Act, which - as Pete blogged a while ago - mandates government "to consider how decisions might help to reduce inequalities associated with socio-economic disadvantage".
What might this mean? Crucially, it means all government decisions - including Budgets - are now open to judicial review if someone can argue that anything hits the poor. Which the IFS have just accused the government of doing in their budget (of which, more later).
And who can sue Osborne for his budget? Paragraph 32 of Harman's Act states that any individual is not prevented "from bringing judicial review proceedings against a public body which has not considered socio-economic disadvantage when taking decisions of a strategic nature". So if anyone makes cuts which Jo Blogger thinks hit kids with special needs, they can have the decision subject to a judicial review. And, perhaps, try to claim legal aid for so doing. The Treasury might claim this is baseless, but they may end up being sued nonetheless - it will be great fun for the unions to find out how far they can go.
In this way, Labour transferred power from parliament (where it was about to lose power) to the courts (where the lefty judiciary reign supreme). Their calculation was that if they did this quietly enough, and in technicalities, the Cameroons would not wise up to it because of their aversion to detail. Cameron should have repealed the Equalities Act instantly.
This morning, we had more than just car crash radio. It was the first skirmish with an enemy the coalition government has not properly appreciated: the new laws designed to trap reforming governments.