Is David Cameron aping Gordon Brown's headline-grabbing habit?

Inside Westminster

It should have been a good week for David Cameron. A collective shudder went through the leading figures of the Labour Party who were watching the BBC's 10pm news bulletin on Wednesday. For the first time they could remember since the 2010 election, the lead story was a positive one about the economy – a 50,000 fall in unemployment in the three months to August.

The bulletin included another good news story for the Government: Mr Cameron's Commons pledge to legislate to ensure that "energy companies have to give the lowest tariff to their customers". If it sounded too good to be true, it was. His statement was news to energy firms – and to Whitehall and his Cabinet colleagues.

His premature announcement unravelled because the Government could not provide any details of how his guarantee would work. Ed Davey, the Liberal Democrat Energy and Climate Change Secretary, was not a happy bunny. In media interviews, he pointedly declined to repeat the PM's pledge, since no such policy existed. Some Liberal Democrats smelt an attempt to steal their thunder because Nick Clegg and Mr Davey have been on the energy tariffs case for several months.

As a result, 24 hours after that positive story about falling unemployment, Thursday's BBC news bulletin led with the shambles, chaos and confusion over the PM's promise on energy tariffs. What should have been positive news had somehow been turned into a negative; it seemed the PM had found a reverse Midas touch. One dismayed Tory minister told backbenchers in the Commons tea room: "It's a multishambles."

There was worse to come for Mr Cameron. On Wednesday night, Conservative MPs gathered for their weekly meeting at 5pm in Commons Committee Room 14. It was their first opportunity to discuss the fate of their beleaguered Chief Whip Andrew Mitchell since his outburst at police officers guarding the gates of Downing Street a month earlier.

With Labour calling for Mr Mitchell's head, and Mr Cameron reluctant to sack a man he appointed to the job only last month, Tory MPs were expected to be loyal to their tribe and rally behind the man in charge of maintaining discipline among them. However, their 30-minute discussion did not go according to Downing Street's script. Four MPs called openly for Mr Mitchell to resign, and three others among the 19 speakers admitted they felt he should have resigned immediately after the incident. It was hardly a vote of confidence. Although the Tory high command insisted the storm was blowing itself out, when Mr Mitchell took his own soundings he realised he could not command the authority of his backbench troops – or even of his team of whips, including his deputy John Randall.

Mr Mitchell finally quit last night. That he clung on to his post for a month leaves a question mark over Mr Cameron's judgement. The Prime Minister was reluctant to throw his Cabinet colleague to the media wolves, believing that Tony Blair was too quick to do so. How Mr Cameron must now wish he had dumped his Chief Whip on day one of the controversy, and declared that swearing at police officers was unacceptable.

By hanging on to Mr Mitchell for so long, the PM risks reinforcing the Tories' damaging image as the "party of the rich" and "out of touch" because of the allegation that Mr Mitchell called the police "plebs", which he still denies. Unfortunately for Mr Cameron, the affair coincided with Tories' attempts at their party conference to revive their "we're all in it together" mantra over spending cuts. It had been put on hold after the Budget's cut in the 50p top rate of tax, with which George Osborne pressed ahead despite being warned that it would be electorally toxic.

Helping hard-pressed householders with their rising energy bills was one part of Mr Cameron's fightback strategy. But now Whitehall officials must scrabble around for a policy on energy tariffs that lives up to his billing. "It's all back to front," one complained, saying the final package was likely to fall short of the PM's words.

Cameron aides insist the false start will be long forgotten by the 2015 election, as long as the Government comes up with a policy that helps people to cut their energy bills. They dismiss this week's language problem as a storm in a Westminster village teacup.

Some ministers are not so sure, rightly pointing out that energy prices are a major concern for millions of voters, who will therefore notice the fiasco. We have had the Budget omnishambles, the West Coast line franchise shambles and now the energy shambles. The worry for Mr Cameron is that, when a government gets a reputation for incompetence, at some point it becomes impossible to shake it off.

Similarly, the PM's efforts to shed what he called the image of "cartoon Conservatives" painted by Labour have suffered another setback with his handling of the Mitchell affair. A week after telling his party conference he is here to "spread privilege", Mr Cameron has again appeared like a man who defends it.