Financial Directors have put the boot into Gordon Brown's economic policy, after an Accountancy Age survey showed a massive and sudden drop in support for the 'iron' chancellor.

In the run-up to what could be his most important Budget, the results of this week's Accountancy Age/Reed Accountancy Personnel Big Question show a large swing against Brown after previous surveys indicated general support for him.

When asked whether their confidence in Gordon Brown's ability to run the economy had fallen, 54% of respondents said 'yes' compared with only 31% who answered negatively.

The results are a damning indictment of Brown's adjusted forecasts on economic growth made in the pre-Budget report last year, which could well be adjusted downwards again.

It is also a criticism of the use of the cash raised from higher taxes and a further blow to the government after a Guardian/ICM poll showed Tony Blair's popularity had fallen sharply over his position on the Iraq crisis.

One FD said: 'I have never considered Gordon Brown to be a very good chancellor, just a lucky inheritor of a strong economy at a time of consumer and general economic growth that was not of his or Labour's making.'

Three surveys for Accountancy Age since April 2002 have shown strong support for Brown with his support rising from 43% of FDs to 64% in November last year. Ruth Lea, head of the IoD policy unit, said: 'Public services do not seem to be improving despite the large increases in spending, the public finances are deteriorating rapidly and the competitiveness of the economy is being damaged. It is time to rethink economic strategy.' Brown's plans will come under further scrutiny today as the Inland Revenue announces its January tax receipts. The figures - which include self-assessment returns - should give the strongest indication yet as to whether there will be a significant gap in the government's finances.