There are some things that as a politician you really mustn’t say – things that suggest your priorities are so wrong, and your understanding of public duty so defective, that you can never be entrusted with anything serious. When David Cameron announced yesterday that, in coping with floods, ‘money is no object’, he said one of those things.

For any responsible politician, money – tax payers’ money – is always an ‘object’. As Mrs Thatcher endlessly reminded her colleagues, the government, itself, has no money, only the money it takes from the people. She was right. To declare that there is no limit to what the government is prepared to take from taxpayers for a particular purpose is worse than populism. It is a fundamental and culpable betrayal of public trust. It is, in fact, not dissimilar to the view espoused by Arthur Scargill thirty years ago, when he was asked by the Commons Select Committee during the miners’ strike, how much a pit would have to lose before it became uneconomic and should be shut. He simply replied that there was ‘no limit’.

It is easy to understand why the Prime Minister said what he did. He was caught out in 2007, when he spent time in Africa rather than in his flooded constituency, and the criticism rankled. He will also, doubtless, have been warned by George Osborne, always so much more concerned with political strategy (and America) than with the boring problems of the public purse, that mishandling flooding – as George W. Bush mishandled the aftermath of hurricane Katrina – spells trouble. More immediately, Mr Cameron is panic-stricken by the campaign, spearheaded by the Daily Mail, aimed at having money taken from the Overseas Aid budget for flood aid back at home.

But, still, ‘money no object’? No one has the faintest idea how much money it will take to address the results, let alone the causes (to the extent they can be determined), of the storms and floods. The Prime Minister sometimes, of course, thinks that green policies can be summed up with a four letter word. But more recently he has suggested that man-made climate change has made the dreadful weather. In that case, the sky is almost literally the limit. At a more prosaic level, Mr Cameron’s pledge will make Owen Paterson, the Environment Secretary’s task a nightmare. How will Mr Paterson be able to resist demands from Lord Smith, or his successor, at the Environment Agency, or the demands of hundreds of drenched communities for public money? How will Mr Paterson be able to say ‘no’ when the insurance companies demand subsidies to cover submersible dwellings? How will people be persuaded to abandon settlements that are simply not sustainable, if there is no limit to what government will spend on their defence?

Writing, as I do, in Cornwall – how will Mr Cameron refuse me the option of not just a speedily restored rail link at Dawlish, but the construction of other alternative rail links, and airport links as well? (Somehow, I think he’ll manage that).

The folly of what he has said will, however, become truly apparent in the lead up to the next election. The best hope that the Conservatives have of beating off Labour, and seeing off UKIP, is by demonstrating the credibility of their economic management. That credibility is now in tatters. Almost all the cuts in public spending intended to bring the structural budget deficit into balance, let alone to allow for tax cuts, have been pencilled in for after the next election. They are paper promises.

But at least the optimists – those who would bet on Messrs Cameron’s and Osborne’s Conservative instincts – could hope that, freed from Lib-Dem obstruction, a Tory government would after 2015 meet its declared objectives. Can anyone now believe that? If open cheques are so easily offered in this emergency, how many more will follow? Far from hoping to see an end to ‘protected’ budgets (the NHS, Education, Aid) we may now see more such protection, and then the busting of any remaining limits whenever the decibels of protest mount.

Mr Cameron has made an unforced error. He knew what he was doing. It fits entirely into a way of looking at politics that his hero, Harold Macmillan, would have understood. That ‘money is no object’ is undoubtedly what people from certain wealthy backgrounds are brought up to believe. It is also why the Conservative Party, until recently, gave up picking its leaders from Eton.

Tags: David Cameron, Floods, Public spending