Some 84 per cent of young people resent being asked for money by street fundraisers, according to a Giving Nation website poll.
G-nation campaign director Andy Thornton said: "We know young people are keen to give, as 75 per cent of them said that they gave to a cause they believed in the last time they were asked. But similarly, 70 per cent feel guilty when they can't afford to give."
The organisation's online forum, www.g-nation.co.uk, encourages awareness of charitable giving among the young and has 12,000 members using its suite of chat rooms, news features and games.
Thornton added: "What we don't always realise is how off-putting it is to be made to feel guilty in a social setting for those at a self-conscious stage of life."