The British public is united in revulsion at the disclosures about MPs’ expenses and many voters have turned against both main parties.

A Populus poll for The Times shows a sharp drop in support for Labour and the Tories and a shift towards the Liberal Democrats and other parties, including the UK Independence Party and the British National Party. The poll was carried out between Friday and Sunday, after the first stories about expenses claims by Labour ministers and MPs but before reports appeared yesterday about Conservative MPs.

Support for Labour has fallen by four points since early April to 26 per cent, just above its low last summer. But the Tories are also four points down at 39 per cent. The main beneficiaries have been the Liberal Democrats, up four points to 22 per cent, their highest for nearly four years. Other parties are also four points higher at 13 per cent. This is mainly spread between the nationalist parties, the BNP, UKIP and the Greens.

The poll shows very high levels of agreement both that “all the parties are as bad as each other” in abusing the system of expenses and allowances (backed by 86 per cent), and that the way MPs have acted confirms “how self-serving and out of touch most are” (85 per cent).

Moreover, most voters dismiss the defence offered by MPs over the weekend that their expenses claims were allowed under the current rules. Four in five voters (79 per cent) agree that, even if allowed, “if MPs had any integrity they would never have claimed for the cost of many things they did claim for, such as furnishings, cleaners and trivial household items”. A fifth disagree.

More than nine out of ten (92 per cent) agree that it is essential that claims are scrutinised and approved by a body that is completely independent of Parliament.

Gordon Brown’s leadership rating has also dropped sharply since his temporary boost last autumn over his handling of the banking crisis: down from 5.04 to 4.47 (on a 0 to 10 scale). This is higher than the low points of around 4 last summer, but is the lowest of any of the three main party leaders. By contrast, David Cameron is up over the past six months from 4.94 to 5.39, the highest level for any Tory leader over the past six years. Nick Clegg is up from 4.08 to 4.71, his highest so far. He has done very well among Liberal Democrat voters and benefited from don’t knows making up their minds in his favour.

But the most popular leader by far is President Obama, whose rating is even higher than when he was elected in November, up from 7.08 to 7.27. This compares with the peak for a British leader of 5.75 for Tony Blair in May 2003.

Labour’s options are limited. Only just over a third (down from two-fifths last August) think a major shuffle of the Cabinet to bring in more fresh faces would improve the Government’s prospects. Nearly three-fifths disagree.

Such is the extent of voter disillusionment that less than half the public (44 per cent, down from 52 in August) believe that the departure of Mr Brown would improve Labour's prospects. But 49 per cent disagree, up from 44 per cent.

The only positive step for Labour would be “significant policy changes in major areas such as the NHS, crime and tax”. This would improve Labour’s prospects according to 54 per cent, with 40 per cent disagreeing.

Populus interviewed a random sample of 1,504 adults aged over 18 between May 8 and 10. Interviews were conducted by telephone across the country and the results have been weighted to be representative of all adults. For more details see www.populus.co.uk .

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