People on benefits are being pushed into debt, ill health and homelessness because of widespread incompetence and communication failures at a key Scottish claims centre, according to frustrated charity staff.

The Citizens Advice Bureau (CAB) has warned that some claimants have battled for six months to get benefits from the Department for Work and Pensions (DWP).

The delays are being blamed on a "call centre" culture at the distribution centre in Glasgow where staff are frequently said to lose paperwork or fail to pass it to other departments.

One epileptic man, according to the charity, lost his home after his medical certificates were mislaid by staff, delaying his benefits by four months - so long he could not pay his rent any more.

He had so little money for food that he suffered a fit brought on by taking his tablets on an empty stomach.

A woman whose payments were repeatedly miscalculated learned that her claim had been "ignored" because it was so complex."

The revelations from the manager of the CAB's Drumchapel branch come a few days after Stirling CAB announced it was going to hand out food vouchers to people made desperate by similar delays.

Problems there were also blamed on the DWP's move from small local centres to giant distribution bases like the Glasgow office - said to be three times the size of the city's Hampden stadium.

A DWP minister categorically denied there were any problems.

But at Drumchapel CAB, manager Hugh O'Neill catalogued countless problems.

He said: "This new centre is supposed to be fantastic but they don't speak to each other. There is no communication between departments, there is a real management problem.

"You used to phone up the local office and speak to one person for everything. Now you get passed from pillar to post and it's taking weeks and weeks for lots of our cases because departments only deal with their own work and they are not familiar with the other departments.

"You speak to one person and they say they will phone you back but you know your inquiry is dead because they don't call back and when you ring again you get someone else and you have to start from the beginning."

He added that the crisis loan scheme, designed to help people hit by payment delays by providing cash help within 48 hours, was also failing.

"I applied repeatedly for a crisis loan for a man with epilepsy which they said was not granted because they didn't have his sick lines. On the third attempt he had a seizure in our office because he had taken his medication on an empty stomach."

One woman, aged 53, who waited six months for back pay from a successful appeal to get her incapacity benefit reinstated, said: "They kept getting the dates and calculations wrong and at one point they admitted that my case had been ignored because it was too complicated and nobody wanted to do it.

"I was really angry. My husband is also on benefit and he has had problems with payments too. We had to cut back on gas and electricity, on everything."

Caroline Flint MP, Minister for Employment and Welfare Reform, said: "There are no backlogs of work in processing benefits claims in Scotland, with all our main benefits being paid on time."

She claimed that crisis loans were "normally" paid within 48 hours and branded the CAB "completely irresponsible" over its "suggestion" that people would need food vouchers.