It has been a very good few days for the head of state, a very bad few days for the head of government.

The current level of the adulation for the monarch is unlikely to be sustained, but a more important question for Britain right now is whether the Prime Minister can recover even some of his authority.

The last thing the UK needs at this time of growing financial crisis is a weak, confused and indecisive Government. One of the reasons why the Queen is so popular is that she simply doesn't have to make the hard choices a political leader must make. But most of David Cameron's decisions these days seem to consist of reversing earlier decisions.

The Prime Minister, once so sure-footed – remember his dignified and moving response to the Saville Report on the Bloody Sunday Londonderry shootings? – is looking more inept with each passing day. Even the Jubilee party in Downing Street was subjected to a sudden U–turn when it was moved inside because of the inclement weather.

Mr Cameron described that party as "a great Big Society occasion". All that served to do was to remind us of the almost forgotten key social concept of his administration. Of course, the architect of the Big Society idea, Steve Hilton, has left Downing Street. Mr Cameron seems increasingly bereft of key allies and supporters.

His closest political pal, the Chancellor, has been presiding over what must surely be a record stint of backtracking on Budget proposals. Mr Cameron claimed on Sunday that "nobody" thought his Government lacked grit, resolve and strength. I'm afraid these are exactly the qualities many voters think have been lost – if they were there in the first place. He also said: "Let's not keep ploughing into a brick wall." If you think about it, that phrase contains an extraordinary admission – that his Government has been ploughing into brick walls on a regular basis.

Mr Cameron and his colleagues had hoped the feeling of warmth emanating from the Queen's Jubilee would somehow stick to their administration. That clearly isn't happening. And even if the coming Olympics are an enormous success, it is unlikely the Government will benefit from that either. Perhaps the most worrying thing for Mr Cameron and his party is that the Liberal Democrats, the junior partners in the Coalition, are becoming, frankly, mutinous. Till recently it was a cliché that the LibDems had to stick with the Coalition because they had nowhere else to go. With Labour now doing well in the polls, it is apparent that many senior LibDems are thinking of a future alliance with Labour – while Labour might still want them, that is. Meanwhile many senior Tory MPs are spoiling for a fight with their own leader rather than the Opposition.

Mr Cameron is clearly not presiding over a united state. He knows that if he makes high-profile interventions in the coming campaign for Scottish independence, that will do his own anti-independence cause more harm than good.

He is beginning to look ominously like Ted Heath about two years into his administration in the early 1970s. Like Mr Cameron, Mr Heath was not a natural hardliner, but early on he adopted a tough industrial posture. There was much talk about refusing to support "lame ducks" – but then he had to change track spectacularly when he was forced to nationalise Rolls-Royce. From then on his Government was noted for policy somersaults more than anything else. Eventually, cowed by militant miners, Mr Heath desperately called an unnecessary early election to answer the question: "Who governs the country?" Not you, was the voters' answer.

The irony in all this is that the Coalition Government has not governed that badly. Even the recent Budget, subject to so much retrospective tinkering, delivered a major political achievement: taking about two million people out of paying income tax. The Government has received zero credit for that, which sums up the problem. Mr Cameron cannot gather credit even when credit is due.