Public Perceptions of Poverty, a report compiled by Comic Relief, is based on responses from 2,000 people to questions asked at regular intervals from December 2004 until January this year.
The proportion of respondents who were "very concerned about poverty in poor countries" fell from 30 per cent in 2004 to 22 per cent.
In the latest round of research, 57 per cent said they knew nothing about trade justice, and only 26 per cent said they strongly believed that the debts of the world's poorest countries should be cancelled in full. This figure was down from 33 per cent in 2004.
Andrew Darnton, an independent researcher who coordinated the results for Comic Relief, said the findings were "broadly depressing".
He added: "People are more aware that the causes of poverty can be political. However, MPH didn't open up the issues of debt, trade and aid to the public, and there are massive gaps in their knowledge, which nobody in the sector has done anything to address."