Are Osborne's days as Chancellor numbered?

This week is likely to prove pivotal in determining George Osborne's long term political future and all the signs are that it is going to look alot less promising by the end of it.

He has to face MPs to explain why he is making almost weekly U-turns on policies announced in what has proved to be one of the most politically inept Budgets of recent years. He cannot come out of that well. Even if nothing new emerges and no political knock-out punches are landed by Ed Balls, it will remind people of just what a mess the Budget has become.

More cricially, this afternoon he will be appearing at the Leveson inquiry, hoping that Gordon Brown's evidence this morning will grab all the headlines. If it doesn't it will be because Mr Osborne has dropped an almighty clanger.

Then, on Thursday he has to make one of the key speeches in any Chancellor of the Exchequer's year when he attends the annual Mansion House dinner in the City. Already, critics of his regulatory reforms are setting the agenda for the debate that will follow this speech: that debate will be conducted on their terms not Mr Osborne's.

The week started pretty badly with a queue of backbench, largely Eurosceptic, Tory MPs forming to rubbish his speech claiming that the Eurozone crisis is seriously damaging the prospects for economic recovery in the UK. This speech was clearly meant to appeal to those very MPs now being so critical of it so their very public rejection is potentially extremely damaging to the Chancellor.

Mr Osborne has never commanded the confidence of the Parliamentary Conservative Party. About a year out from the General Election in 2010 there were several senior backbenchers privately trying to persaude David Cameron that Mr Osborne was a liability and that he should be replaced as Shadow Chancellor before entering the crucial election year. Mr Cameron sent these critics packing with a clear message that he and George stood or fell together. I wonder if he still feels the same unequivocal loyalty to his Chancellor today?

The hostility provoked by Mr Osborne's weekend speech shows that those backbench critics no longer feel the need to be discreet about their lack of confidence in their Chancellor. This leaves him poltically vulnerable and while it is extremely unlikely that the Prime Minister will for a moment consider changing Chancellor in the re-shuffle that it now thought to be on the cards for this summer, I can see a change before the next General Election, perhaps in a summer 2014 shake-up of the government as the clock ticks down to the next General Election.