Gordon Brown's hopes of a "Beijing bounce" on the back off Britain's Olympic success were dashed last night with an opinion poll putting the Tories on a record 24-point lead over Labour.

Gordon Brown's hopes of a "Beijing bounce" on the back off Britain's Olympic success were dashed last night with an opinion poll putting the Tories on a record 24-point lead over Labour.

As the Prime Minister prepares to fly out to China for the closing ceremony of the Games with his thoughts firmly fixed on reviving his fortunes in an autumn relaunch, the latest monthly Ipsos/Mori poll put Labour on a 30-year low with the voters.

Mr Brown's own personal ratings showed 71% of people were dissatisfied with his performance, including 39% of Labour supporters.

Among the 1005 voters polled by telephone between August 15 and 17, twice as many who said they were "absolutely certain to vote" said they would vote Conservative as Labour, 48% to 24%, at the next General Election, which is the biggest gap recorded since the pollster's records began in 1977.

This is four points wider than a month ago with the Tories up one and Labour down three. Among those simply stating a preference on how they "intended" to vote Labour does slightly better but is still well behind David Cameron's Conservatives on 28% to 42%, giving the Tories a 14-point lead, down two on last month.

The snapshot also showed more than three-quarters are unhappy with the way the UK Government is running the country, 76% to 20%, and most, 58%, now believe the Conservative opposition is ready for office. Crucially perhaps, the Tories remain well ahead on their ability to run the economy, 38% to 23%, the issue considered most important by voters, yet 72% believe things will get worse in the next year. The poll respondents said they now have more faith in the Conservatives on every aspect of policy apart from health where Labour is ahead by three points.

Mr Cameron enjoys a 51% approval rating, supported by all but 14% of his party's supporters, and is considered the more capable to lead the country out of the present economic situation by 50% to 29%.

The Liberal Democrats were up one on 16% among those certain to vote but down one from 18% to 17% among all those stating a preference.While a third said leader Nick Clegg was doing a good job compared with 26% stating their dissatisfaction, a larger number, 42%, expressed no opinion.

Ipsos/Mori said its previous low score for Labour was 27% and that it believed the 24-point gap was the biggest ever seen in a telephone-based poll.