Labour's 1997 pledge to clean up British politics has failed to turn the tide of public mistrust.

"Sleaze" became the defining issue of the 1997 general election and despite Tony Blair's fervent vow to be "purer than pure" only one in ten (11 per cent) of the general public trusts politicians to tell the truth in a tight spot - an all-time low.

And as voter turnout drops, trust in government also continues its decline, finds the latest British Social Attitudes survey published by the National Centre for Social Research.

In 1974, almost four out of ten voters trusted British governments to put the country's needs above those of their political party "most of the time", today fewer than two out of ten, 16 per cent, do so.

As concerns about increasing voter "apathy" grow there is little sign of politics flourishing elsewhere, with only 16 per cent attending a demonstration compared to 21 per cent in 1998.

And contrary to the claims of some green activists, young people are less concerned about the environment than the middle-aged.

The proportion of young people signing environmental petitions fell from 50 per cent in 1993 to 31 per cent in 2000, making those in their 40s and 50s the most likely to have signed up to the green agenda.

The key factor in falling public trust is the decline in party-political identification, finds the research.

In 1987 almost 46 per cent felt strongly or fairly strongly attached to the party they supported at the polls. Now only 32 per cent feel the same way.