The prime ministerial code (a very special form of the Ministerial Code) was best expressed by Gordon Brown. He said of the Damian McBride affair: "I take full responsibility and the person responsible has resigned."
The Prime Minister knew exactly who to blame: the Speaker. The little pipsqueak had called him out of important local election meetings to rehearse in the House all the questions he had answered the week before.
The Labour Party was equally clear. To blame were the PM, the minister, the minister's adviser, the Murdochs, the party they represent, the class they come from, and the limb of Satan who spawned their tribe shortly after the Fall.
The Urgent Question squeaked into the last moments of the longest parliamentary session since the early 13th century.
There was a very great deal of noise, some creative groaning, much shouting and pointing, and artillery barrages of the bench monkeys going "Hoo-hoo-hoo!" Actually, they were hooting "You! You! You!" as Cameron insulted their leader with the words "Weak! And wrong!" He may be getting a little too rude for someone of his elevation.
Tory shouting probably had the edge (guilt and shame are great unifiers). But some of Cameron's rejoinders were masterly. Chris Bryant accused the Culture Secretary of showing the Murdochs his statement two days before the Commons heard it. Cameron declared Bryant was not one to talk – he had used privileged information himself to make untimely and unfounded accusations: "A man of honour would stand up and apologise!" Tony Blair couldn't have put it better.
Cameron retained and even buffed up his prime ministerial sheen. By repetition, the merits of Leveson are persuasive. It's on TV and on oath. A civil service inquiry would have to denounce the Permanent Secretary – and that's against its own code.
But Ed Miliband also made a good case well. He came as close as he has to "beating Cameron at the despatch box" as he promised his party last year. There may be three more years to see if he can.