Less than a third of young people express any interest in politics, according to an official survey.
It found 31% of 16 to 24-year-olds were fairly or very interested in the subject, compared with about half of those aged 55 and over.
But almost two-thirds of adults of all ages thought they would be seriously neglecting their duty if they failed to vote, the Office for National Statistics (ONS) said.
40,000 households were questioned.
The analysis was based on research conducted in 2011-12 by the Institute for Social and Economic Research at the University of Essex for its UK-wide Understanding Society survey.
Of those in the youngest group - aged 16 to 24 - 42.4% stated that they had no interest in politics. This fell to 21% for over-65s.
The survey's publication follows a row over comedian Russell Brand urging people not to vote because all politicians are corrupt and untrustworthy.
But it is broadly in line with findings last year in the British Social attitudes survey, which found that older people were more likely to see it as their civic duty to vote and had a stronger party allegiances than the young.
This research suggested the younger electorate were becoming increasingly disengaged with the democratic system - but it also suggested they were more likely to express themselves politically in other ways, such as boycotting environmentally unfriendly products.
Younger voters have significantly lower turnout rates at elections than the middle-aged and elderly, with only 44% taking part in the 2010 general election.
However, the ONS survey suggests that this is not echoed in the level of contentment with the UK's political system.
Just 45% of the 45 to 54 age group said they were quite or very satisfied with the way democracy works, compared with 52% of those aged 16 to 24.
Will Brett, head of media at the Electoral Reform Society, said: "It suggests that young people simply aren't as cynical. It suggests there's an opportunity here. Maybe young people have more faith in the system and the key thing is not to waste that opportunity."
Mr Brett added that many young people were becoming involved in politics in more informal ways, such as social media campaigns, but he added: "We need to find ways of getting them more interested in our system of representative democracy. It's extremely precious."