Andrew Grice: Prime Minister will stand by his man – but for how long?

David Cameron's return to the political fray after the birth of his daughter was not supposed to be like this. An original plan for him to mark the new political season with a Downing Street press conference was quietly dropped when he realised he would be besieged with questions about his communications director, Andy Coulson, and the private life of his Foreign Secretary, William Hague.

However, at Prime Minister's Questions today, Mr Cameron is unlikely to escape questions about telephone hacking at the News of the World under Mr Coulson's editorship. He will doubtless stand by his man. The view in Team Cameron is that nothing has changed and that very little new has emerged in recent days to cast doubt on Mr Cameron's decision to give Mr Coulson a "second chance", by hiring him and then taking him to Downing Street with him in May.

But political pressure over the hacking controversy shows no signs of abating. True, it is being whipped up by Labour, which has an obvious interest in doing so. But there is also a very long list of potential and actual victims of phone hacking. As more names emerge, that keeps the story going. Some of them may take legal action, prolonging the agony.

Alastair Campbell's dictum that a politician has to resign if he is "the story" for about two weeks running was never an iron law but it is a pretty good rule of thumb. Tory aides believe the Coulson storm, now six days in, will blow itself out before a fortnight is up because of the absence of new facts.

As they devour Tony Blair's memoirs for lessons to be learnt, the Cameroons will draw mixed conclusions about sackings. The former prime minister now regrets Peter Mandelson's two resignations from the Cabinet. He admits he should not have bowed to media pressure for a scalp over Lord Mandelson's £373,000 home loan from Geoffrey Robinson. Equally, Mr Blair is open to criticism for not letting go of Mr Campbell quicker after he became "the story". Such judgements are easy to make after the event; sackings are not an exact science.

Mr Coulson undoubtedly calls the Government's media shots but being part of the Coalition adds another layer of complexity. Some Liberal Democrats have expressed concern about the hacking affair and that spells more trouble (and headlines) than it would if Nick Clegg's party were merely in opposition. Caroline Pidgeon, leader of the Liberal Democrat group on the London Assembly and a member of the Metropolitan Police Authority, said: "So far it seems the Met's investigations have been far too narrow. This should not be an issue of political point-scoring, but simply ensuring that serious allegations about illegal phone tapping and the invasion of privacy of so many people are now properly addressed."

The dog that has not barked at Mr Coulson yet is the Conservative Party. Privately, some Tory MPs are uneasy about the spate of headlines the communications director has generated. Critics don't doubt he is good at his job but some question his determination to get good headlines in the Daily Mail and The Sun even if it means upsetting other papers. Mr Coulson has his enemies inside his own party; it was ever thus because those outside the inner circle are often jealous of those who are in it.

A new disclosure could tip the balance and make it a question of Mr Cameron's judgement, which would be bad news for Mr Coulson. But we are not there yet.