If Cameron falls will it be erosion or the silver bullet?

During the last few weeks I have been watching the developing crisis around the News of the World hacking scandal with growing unease. I'm fairly certain that we haven't yet heard the worse of the allegations, though how that could be more serious than hacking a missing teenager's mobile phone I'm not certain.

Even so new stuff is coming out all the time. Who expected the revelation that the Metropolitan Police Commissioner would have accepted a freebie worth £12,000? On its own it would have been serious but the links with the hacking investigation proved lethal for the Commissioner's career.

We now have a stand off between a media group that has already shown it can act like like a feral beast, a police force that feels and fears that it will be made a scapegoat, and a political elite that is puzzled by what to do next.

Bear in mind that the media group has plenty of ammunition. They know who was bribed, they know who was compromised by hospitality and bribes. Newspapers often have a handy store of information about individuals which they don't always print or follow up.  In future weeks that material will be used tactically against individuals. This is not new.

The police have had a kicking from the politicians. Two senior officers have gone. Once again policemen have a memory. Sometimes they forget, later they recall. One rule that says Cameron can employ former NOTW journalists, another that says Scotland Yard can't. That doesn't look right.

A second issue that needs to be looked at is the enhanced role of the Mayor of London in supervising the Met. Until Boris was elected that power resided exclusively with the Home Secretary. With two commissioners lost in three years and a major scandal underway we need to ask whether Johnson's role has been helpful. 

Cameron has already had to shorten his trip to Africa. That's a move usually reserved for a major catastrophe such as a natural disaster or a terrorist attack. Likewise with the extraordinary decision to extend the sitting of the House of Commons for a day, again a sign that things have gone serious;y wrong.

For Cameron there will be two possible man-traps. Scenario one is that the war of words, the arrests, the accusations gradually erode his authority within the Conservative Party and with his coalition partners.

It has been interesting to see that virtually no Tory MPs are prepared to be wheeled out to defend him. The Cabinet is ominously quiet and fellow Old Etonian Boris Johnson didn't rush to Cameron's defence when offered the opportunity. Such erosion takes its toll and this may bubble to the surface by the time of the party conferences in the early autumn. There are many Tories who are unhappy with the coalition. So far they have kept quiet but circumstances are changing fast.

Then there are the Lib Dems. Many of my Tory contacts speak with pleasure at the delight of Lib Dems to having Ministerial red boxes and chauffeured limousines. It is just about conceivable that they may make a dash for the moral high ground with Vince Cable as leader and seek to re-establish themselves as a seperate party able to do a deal with Labour.

That is the erosion route. There may however be a "silver bullet", just as there has been on several times over the last fortnight. One did for the NOTW, one did for Stephenson. Is there one waiting for Carmeron?

No Prime Minister has ever looked forward to the recess than David Carmeron does tonight. General election in the autumn? It would actually suit a lot of MPs who now face loosing their seats by the impending boundary review. Might be worth asking Ladbrokes for the odds.