George Osborne, the Chancellor, has been found out. This newspaper took the view two years ago that the new government had made the wrong choices on tax, public spending and borrowing. It is hard to know what would have happened if the policy of Alistair Darling, the former Chancellor, of halving the rate of borrowing in four years had been followed instead. It might not have made much difference, but our judgement is that it would have sustained economic activity and avoided part of the downward cycle of rising unemployment, reduced private spending and the rising cost of state benefits.

What cannot be denied, however, is that things have not worked out as Mr Osborne hoped. The Chancellor admitted in the Budget three months ago, and repeated at the Mansion House last week, that his plans to cut public borrowing are now on a different track. As John Rentoul writes on page 41, it looks as if he and David Cameron have reverted to their previous economic policy of making it up as they go along.

Since the Budget, indeed, Mr Osborne's reputation as a clever political strategist has been torn to shreds. The downward revision in growth forecasts, the cut in the top rate of income tax and the proposed pasty, caravan and charity taxes (now abandoned) have all undermined his credibility. Our ComRes opinion poll today lays bare the extent of the damage. Majorities of voters agree that the Chancellor is "out of touch", "too posh" and "comes across as arrogant". That would be bad enough, but the worst finding is on his competence: 48 per cent agree that he has "made too many mistakes to be taken seriously", and only 25 per cent disagree. (The rest have no opinion.)

This is the culmination of a long process. It was early on that Mr Osborne began to acquire a reputation for implausible excuses when he blamed snow for slower-than-expected growth. More recently he has suggested that, with hindsight, some of the Budget measures were misconceived. But politics demands foresight and Mr Osborne chose to spend the week before the Budget in America with the Prime Minister rather than exercise it. Now the Chancellor's all-purpose excuse is the crisis of the eurozone, even if, as shadow Chancellor Ed Balls points out, Britain's exports to the euro area remain surprisingly buoyant.

The Chancellor should heed the wise words of his cabinet colleague, Eric Pickles, who told The Independent on Sunday last weekend that people ought to stop blaming others and start taking responsibility for their own decisions – albeit in relation to troubled families.

We wish that last week's plan to fund £5bn a month of new bank lending marked a change in the Chancellor's economic approach, but we suspect that most commentators are right when they say that it is unlikely to make much difference.

If Mr Osborne will not bow to the economic arguments against his policy, then perhaps this most political of chancellors will yield to the weight of party advantage. For the other message of our poll is that the Labour lead is into double figures, and it would be dangerous for him to assume that this is "just mid-term blues". As the Prime Minister's chief adviser, Mr Osborne must see the threat from Ed Miliband's increasing confidence. In his exclusive interview with us today, the Labour leader depicts Mr Cameron as "the last gasp of the old", and aligns himself with Barack Obama and François Hollande in trying to release the "grip of centre-right austerity".

Mr Osborne should act now to dispel the suspicion that, like the National Government in the 1930s, he is in the grip of a backward-looking ideology. That requires not a cosmetic adjustment but a real change.