GPS in Glasgow are being advised not to help patients who could be exempt from the 'bedroom tax'.

Doctors say that because of a raft of welfare changes, 20% of appointments are being taken up with requests for letters appealing benefit cuts.

They say it is already compromising care for other patients.

The body which represents GPs across NHS Greater Glasgow and Clyde is now advising doctors not to provide letters to support claims against benefit cuts.

In a letter to surgeries, the Glasgow Local Medical Committee (GLMC) said GPs were "not in a position to police the benefits system" and are "not resourced" to provide the service

Letters currently supplied by GPs to support appeals against cuts to other benefits including Disability Living Allowance can cost between £50 - £120 and claimants can be entitled to legal aid.

Legal experts said claimants facing a reduction in housing benefit under the 'bedroom tax' may be entitled to appeal for support in the same way.

Doctors say claimants who require an extra room on health grounds, including for a carer's use, are already known to the authorities and that letters are not necessary.

However they say many are being advised to get GP letters by the Department for Work and Pensions.

Glasgow City Council is requesting letters from people applying for the Additional Room Allowance.

Georgina Brown, secretary of the GLMC, and a GP in Springburn, fears doctors will face a deluge of patients who are desperate to avoid a 14% cut in housing benefit for a spare room.

She said: "Because of the changes to benefit it has gone from doing one of these letters to doing two or three a day.

"Twenty per cent of patients who come in want letters.

"Many are being instructed to do so by the DWP.

"What we are trying to say to the DWP is that you already have this information. It's very poor collaborative working.

"It has got to the stage where access is being reduced. In one day I did three letters.

"Blocking appointments for letters is not appropriate."

Councillor Matt Kerr, Executive Member for Social Care at Glasgow City Council, said: "A GP's letter is only one of a number of sources of evidence we accept in support of a claim for the additional room allowance.

"But with the clear link between poverty and poor health, it is unfortunate that GPs have taken this stance."