Political knowledge among young people has fallen considerably over the past 25 years, according to a study published on Wednesday.

In a survey of teenagers for the Economic and Social Research Council, 40 per cent said they "never" discussed politics with their friends, compared to 30 per cent in 1976.

Nearly half of those questioned believed that there were "about 100" members of Parliament when there are actually 659, while nearly a quarter did not know that the UK is a member of the European Union.

In the same survey conducted 25 years ago, only nine per cent were unaware of Britain's membership of the then-EEC.

Only 10 per cent were aware that referenda can be held in this country.

Nearly two thirds of those questioned claimed that government was "too complicated for them to understand", although a majority believed that ministers could be trusted.

"We set out to discover how much tomorrow's citizens know about the workings of our democracy, and we compared the results with similar surveys undertaken in 1976," said report co-author, Dr David Halpern.

"We found a worrying lack of knowledge of the basic facts and a large scale of apathy that should concern politicians of all parties.

"But we also found the majority of young people were keen to play their part in their local communities."

Of the 1249 teenagers surveyed, more than 75 per cent had engaged in some form of civic activity outside of school.

Of those, 45 per cent have become involved in fundraising, 34 per cent had signed a petition, while a quarter had taken part in scouting or guiding activity and 17 per cent had helped the elderly.

Just over half believed it was important to "do something to improve your community or society", compared to 10 per cent thinking it unimportant.

The survey found that girls were most likely to volunteer, as were children whose parents were politically or civically engaged.

Those who watched the most television were least likely to volunteer, although those who watched a large amount of television news were most likely.

"Students who were at schools with civic education built into the curriculum proved to be more knowledgeable about civic and political issues and more likely to become active in their local communities," added co-author of the report, Professor Peter John.

"Much of the study was undertaken just before citizenship became a curriculum requirement in September 2002 and such lessons should help.

"But engagement depends on more than civic education. Young people are far more influenced by the behaviour and attitudes of their parents and school. Encouragingly, there was considerable willingness by young people to engage with their communities.

"Most young people want to be socially engaged - but not necessarily in the ways that politicians have traditionally focused on."