As far as I can gather, the sequence goes like this:
David Cameron and David Davies had a confidential meeting with Tony Blair and John Reid to discuss ideas for combatting terrorism. Cameron suggested some useful ideas which the government decided to adopt.
Gordon Brown then leaked these ideas to the press as his own. Cameron is furious. The media find out and the story runs as Brown is jeopardising a cross party consensus on terrorism for his own benefit. Blair apologises for Brown's bad behaviour.
But the really interesting thing is that, according to Matthew Parris, it was Tony Blair who leaked the unflattering picture of Brown putting partisan politics ahead of fighting terrorism. Ouch! It seems that intra-party politics is still more vicious than the battle between the parties, let alone the War on Terror.