It is one of those peculiar permutations of coalition politics that George Osborne can consider himself very grateful to Lord Oakeshott, the Liberal Democrat peer and former Treasury spokesman, who has effectively called for the Chancellor to be sacked. Lord Oakeshott took to the airwaves (where he spends a considerable amount of his time) after the announcement of dire GDP data yesterday, to say that Osborne was performing as if on “work experience” and ought to be replaced by a more substantial figure. By that he meant Vince Cable, the business secretary, on whose behalf Oakeshott is often deemed to be speaking. Cable later on stirred the speculation further by suggesting immodestly that he “probably” would make a decent Chancellor, but this morning he publicly reined in his ambitions. He is a team player, he insisted, and Osborne leads the Treasury team.

There is, it has to be said, absolutely no chance of Cable being made Chancellor in this government. Really none at all. Zilch. The job would never go to a Lib Dem – its occupation by a Tory is part of the agreed fundamental architecture of the coalition. Cable will be lucky to stay in the cabinet at all in the next reshuffle. He has never been an ally of Nick Clegg in whose office he is seen as a grandstanding maverick and potential leadership threat. Even in opposition there was resentment of the way that Cable was held up as a mighty authority on economic matters – “St Vince” – poaching precious publicity from the leader. That feeling has since been exacerbated by a very personal irritation that Clegg has become the hated symbol of the u-turn on tuition fees, taking the full force of a vicious public and political backlash, when Cable ran the department that actually implemented the policy and yet escaped with hardly a scratch.

From the Tory point of view, Cable is a leftish fifth columnist. The recent revelation that he sends approving text messages to Ed Miliband will only reinforce the feeling among many Conservatives that the Business Secretary’s natural place is carping from the back benches.

But before the chatter about Cable started up, there were plenty of Tories willingly speculating about the need to move Osborne from the Treasury. Even quite loyal MPs were muttering about weaknesses in the heart of the machine and pointing accusing figures at Number 11 Downing Street. The charges are: the bungled budget, clumsy handling of the ensuing u-turns, suspicion that Osborne spends too much time in Number 10 plotting political attacks and not enough time running the economy, a broader feeling that there is no long-term strategy for winning an election other than hoping that Ed Miliband’s bubble bursts, over-reliance on short-term tricks and tactical manoeuvres, an obsessive personal animosity towards Ed Balls that is unseemly in one of the highest offices of state, a failure to develop a consistent message on what the government is doing to spur growth. There is a feeling on the Tory benches that Labour have been let back into the debate on the economy when they seemed wholly shut out of it a year ago.

In recent weeks I have heard William Hague, Michael Gove and Phillip Hammond all talked up by their fellow Tories as potential Chancellors. The surest way to kill that chatter is for a Lib Dem to pipe up and say Osborne should be sacked – and replaced with Vince, of all people.

There was never really any chance of Osborne being moved in the reshuffle. It would be an admission of economic failure on an epic scale and he is too close to Cameron. The Prime Minister is generally loyal to his friends – witness how hard it was for him to let go of Andy Coulson and how tenaciously he has clung to Jeremy Hunt. Of course in those cases there as an element of self-preservation. Losing high profile figures over phone hacking would have removed protective firewalls around Number 10. But it is also generally said of Cameron’s clubbable nature that he looks after his chums – which can, of course, be interpreted as a good a bad thing in politics depending on whether it is a mark of constancy or corruption. Cameron has ever fewer friends and Osborne is vital.

But it follows from that analysis that the Chancellor is practically unsackable. Yet he is also badly damaged and all those hostile whispers from his own side can’t be unwhispered. That leaves a feeling in Westminster at the start of the long summer recess that the Tory duamvirate’s strategy is essentially to build defences around the hole they are in and frantically keep digging.