Britain's welfare payments are "manifestly inadequate" and fail to live up to the requirements of the European social charter, an influential body has found.

In a damning report which challenges the perception of an overly-generous British benefits system, the European Committee of Social Rights criticised low payments offered by incapacity benefits, job seeker's allowance and the state pension.

"This damning indictment of the UK's appallingly low levels of social security, even before the most recent cuts, exposes the shameful way the unemployed, sick and disabled are treated," PCS union general secretary Mark Serwotka said.

"It ought to nail the lie once and for all that anyone chooses a life on benefits or comes here from another country just to claim them."

The committee found that the UK was "not in conformity" with article 12 of the European social charter, to which it is a signatory, because of the low levels of payments offered by its social security system.

"The minimum levels of short term and long term incapacity benefit is manifestly inadequate," the report said.

"The minimum level of state pension is manifestly inadequate.

"The minimum level of job seeker’s allowance is manifestly inadequate."

Short term incapacity benefits stand at £71 a week, while long term are set at £94.

Job-Seekers allowance stands at £67 per week and the state pension at £102.

The payments do satisfy the requirements of the European code of social security but they do not reach the benchmark set by article 12 of the social charter, which is of 40% of the Eurostat median equivalised income.

Speaking in the Commons today, leader of the House Andrew Lansley said: "It is lunacy for Council to say welfare payments should have increased."

The findings come as David Cameron prepares for a substantial Tory rebellion demanding an extension of restrictions on Bulgarian and Romanian workers.

The debate around the ending of restrictions saw numerous Tory and Ukip commentators suggest migrants were coming to the UK to make use of its generous welfare payments.

In response, the coalition announced plans to prevent new arrivals claiming benefits for two years.

But a recent European Commission study found the perception of welfare tourism to be "a myth".

It found the overwhelming majority of those who move from one EU country to another do so for work and not to receive social benefits.