A new poll shows support for the PM continuing to fall, and Labour trailing the Tories by 20 points.

The Populus survey shows Labour has dropped four points to 25 per cent, while the Opposition gained five to 45 per cent and the Liberal Democrats went up one to 20 per cent.

With a crucial vote on 42-day detention without trial just two days away, it put voter approval for the extension, assuming safeguards were introduced, at 75 per cent with just one in five opposed.

But Gordon Brown's personal popularity fell below even the worst level endured by ex-Conservative leader Iain Duncan Smith.

Mr Brown's rating fell to 3.9 out of ten, the first leader of any party to drop below four since the rankings were introduced five years ago.

There was bad news for David Cameron's party too, with the number of voters believing it was affected by financial sleaze soaring amid a slew of expenses controversies.

The number of voters believing his party is tainted by financial sleaze is up ten points, to 61 per cent.

Populus interviewed a random sample of 1,508 adults between June 6 and 8.

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