Media playback is unsupported on your device Media caption Dame Anne Begg: "Government must tread carefully" over planned changes

The government must ensure new welfare assessments planned for disabled people are "accurate and fair" before they are rolled out nationally, MPs have said.

The Work and Pensions Select Committee said the tests for the new Personal Independence Payment, coming in from 2013, could cut funds people relied on.

The assessments risk being too narrow and missing wider factors, the MPs say.

The government says "a new face-to-face assessment and regular reviews" will ensure "the right levels of support".

The committee said there were "high levels of anxiety" among claimants of Disability Living Allowance (DLA), about its replacement with the new PIP benefit for those of working age.

While the Treasury had projected 20% savings from PIP, it remained unclear who would lose out, the committee said.

The MPs fear the assessment for PIP could focus too narrowly on medical definitions, ignoring environmental factors such as a disabled person's access to public transport.

Under the current system there are hundreds of millions of pounds of overpayments and underpayments Spokeswoman, Department for Work and Pensions

"The government needs to be certain that the new assessment procedure is accurate and fair before it is introduced," said chairwoman Dame Anne Begg.

"Otherwise, there is a risk that people with serious disabilities and health conditions will lose the money they rely on to meet the additional costs incurred as a result of their disability - costs such as maintaining wheelchairs, using specially adapted cars, or paying for help to ensure they can live independently."

The committee wants a national roll-out of the assessments only after a limited regional trial had proved successful.

A Department for Work and Pensions spokeswoman said: "Under the current system there are hundreds of millions of pounds of overpayments and underpayments and 70% of people get the benefit for life without systematic checks to see if their condition has changed.

"We are replacing DLA with Personal Independence Payment and introducing a new face-to-face assessment and regular reviews to make sure people are getting the right levels of support."

'No guarantee'

She added that discussions with disabled people and organisations had already resulted in "significant changes ... improving the assessment and making it fairer".

PIP is contained in the controversial Welfare Reform Bill, which has suffered repeated defeats in the House of Lords.

Image caption Disability Living Allowance is paid to 3.2 million people

Disability campaigners welcomed the MPs' report.

Richard Hawkes, chief executive of disability charity Scope, said: "The government wants to create a more targeted payment. But if it goes ahead with the proposed assessment there is no guarantee that support will go to the people that need it."

Simon Shaw, of deafblind charity Sense, urged the government "to change the way it assesses people while there is still time".

"Blind, partially sighted and other disabled people must not find themselves forced to go through lengthy, costly and stressful appeals processes to get a fair outcome," said Steve Winyard, head of policy and campaigns at RNIB.