David Cameron facing big Commons test on hacking

Wednesday was supposed to be a day of rest for MPs, the first day of their summer break; instead it will be a crucial test for David Cameron in the cockpit of the Commons.

I don't see how the hacking scandal costs Mr Cameron the premiership - but it could still do him very serious long-term harm.

On Wednesday, for pretty much the first time, he will have to see off direct accusations against him in a full-dress Commons debate - not just for ten minutes or so at at Question Time, before the questions move on, but for some hours, facing almost unlimited forensic questioning from his critics, against - doubtless - a background of furious tribal baying from Labour MPs.

It will be a test of nerve, of coolness under heavy fire, and of party solidarity. Some Conservative MPs murmur that this story only mushroomed because of Mr Cameron's decision to hire ex News of the World Editor Andy Coulson - and they're pretty miffed to see the government engulfed as a result.

As always on these occasions, friendly fire is ten times more deadly than broadsides from the Opposition, and it is not impossible that Conservative Coalition-sceptics or simply Tory MPs who don't like what they've heard of the actions of the NoW may give their leader a very hard time - although they would have to be very brave to do so.

But the political importance of the PM's performance cannot be underestimated. If he can demonstrate he has the parliamentary firepower to repel borders he could, finally, get ahead of the scandal; if he can't, the sharks will start to circle.

Conservative MPs are in a skittish mood at the moment. The state of the economy, events in Europe, spending cuts yet to bite, inflation and the expectation of more bad headlines would be enough to make any governing party nervous, even without hacking; with hacking, a nervy hesitant performance would put blood in the water.

So tomorrow will be more than the normal PMQs bear garden. Labour MPs sense a chance to do some serious damage to the coalition…