The public increasingly believe that individuals live on benefits as a result of their own laziness rather than an unfair society in which they cannot find work, the Joseph Rowntree Foundation study concluded.

Attitudes towards benefit claimants hardened most significantly among Labour voters over the last 30 years, the research said.

The analysis is likely to fuel the debate inside the Labour Party over its stance on benefits reform.

Ed Miliband is under pressure from some of his MPs who fear that Labour is seen as soft on welfare and risks becoming known as “the benefits party”.

Under Mr Miliband’s leadership, Labour has opposed reforms including charges for spare bedrooms in social housing, and the benefits cap.

The JRF study, conducted by NatCen Social Research with figures from the British Social Attitudes survey, found that Labour voters increasingly held the view that benefit claimants are undeserving.

In 1987, only 16 per cent of Labour supporters said that people would “learn to stand on their own feet” if benefits were less generous. But by 2011 this had risen to 46 per cent, the research found.

Among the general public of all political persuasions, fewer people now believe that injustice in society is causing poverty and welfare claims, while more feel that individuals’ own “laziness or lack of willpower” are to blame.

Liz Clery, Research Director, NatCen Social Research, said the public were less likely to believe that spending taxpayers’ money on welfare would help tackle poverty than in the past.

“In addition, the British public appear to have become more united in their attitudes to poverty and welfare over the past three decades,” she said.

“Differences in attitude that we might in the past have associated with older people and Labour Party supporters have become much less distinct.”

Julia Unwin, chief executive of JRF, said the findings underlined the “increasingly tough stance” the public are taking against welfare recipients.

“We appear to be tough on those experiencing poverty but not tough on its causes,” she said.

The British Social Attitudes survey found that twice as many people as 20 years ago now believe the unemployed could find a job if they wanted one.

Senior Labour MPs fear that the party has been slow to catch up with the hardening attitudes of voters towards benefit claimants.

Mr Miliband has opposed many spending cuts, including the £26,000 a year cap on welfare per family, cuts to housing benefit for families with a spare bedroom and a below–inflation increase in most handouts.