Of those questioned, 89% said they think people are still judged by their class - with almost half saying that it still counts for "a lot". Only 8% think that class does not matter at all in shaping the way people are seen.

The poorest people in society are most aware of its impact, with 55% of them saying class, not ability, greatly affects the way they are seen.

Gordon Brown claimed at this year's Labour conference that "a class-free society is not a slogan but in Britain can become a reality". But even the supposedly meritocratic Thatcher generation of adults born in the 1980s appear to doubt that: 90% of 18-24 year-olds say people are judged by their class.

The poll also shows that after 10 years of Labour government, social change in Britain is almost static. Despite the collapse of industrial employment, the working class is an unchanging majority. In 1998, when ICM last asked, 55% of people considered themselves working class. Now the figure stands at 53%.

Of people born to working class parents, 77% say they are working class too. Only one fifth say they have become middle class.

Despite huge economic change and the government's efforts to build what it calls an opportunity society, people who think of themselves as middle class are still in a minority. In 1998, 41% of people thought of themselves as middle class, exactly the same proportion as today. The upper class is almost extinct, with only 2% of those who answered claiming to be part of it.

The poll paints a picture of a nation divided by social attitudes and life-chances, with 47% of those living in south-east England considering themselves middle class, against 39% in the north and 35% in Wales and the west.

Northern England remains a working-class heartland, with 57% of people describing themselves as part of it.

Scots - 47% of whom think they are middle class - are just as class-bound as English citizens. Almost half of Scots say that class plays an important part in the way people are judged by others.

Social change is taking place slowly. The middle class has grown: although 41% of people think they are part of it, only 32% say their parents were. In 1998, 69% of people thought their parents were working class. Now only 63% say so, and of those only 53% say they are working class themselves. That shift mirrors the attitude of the former deputy prime minister John Prescott, who admitted "I'm pretty middle class" despite his working class origins.

But many class attitudes have survived economic change. That suggests people are still judged by where they come from rather than how much they earn.

· ICM Research interviewed a random sample of 1,011 on October 17-18. Interviews were conducted across the country and the results have been weighted to the profile of all adults. ICM is a member of the British Polling Council and abides by its rules.