Tens of thousands of sick and disabled people in Scotland face being forced on to unpaid work programmes under threat of losing their benefits from tomorrow.

That is when disability claimants will become eligible for controversial mandatory "workfare" placements, according to new plans which have been quietly drawn up by the Department for Work and Pensions (DWP).

People with a range of physical or mental health conditions could find themselves stacking shelves in high-street stores such as Tesco and Poundland, or cleaning private homes, under the new proposals.

Since the Government's Work Programme began in June, tens of thousands of job seekers have been put on unpaid placements. Now some ill or disabled people are to be told that they must take unpaid positions or risk losing up to 70% of their employment support allowance (ESA).

Ironically, the new measures are coming into effect on the International Day of Persons with Disabilities. A series of national protests against the Government's workfare programmes will take place this week.

Leading Scottish charities have expressed serious concerns about people with disabilities being forced on to compulsory work placements.

Across the UK, some 340,000 disabled people have been placed in the work related activity group (WRAG), which means they must undertake a range of activities to help them get back to work, including training, job-hunting – and now mandatory work placements.

According to a leaked DWP memo, seen by the Sunday Herald, the new strategy is "in line with the view that long-term absence from work is bad for the health and well-being of individuals and their families". The memo goes on to say that employers should make "any reasonable adjustments" for disabled workers on mandatory placements.

Most disabled people welcome support to get into the labour market, but compulsory placements rarely work, says Richard Hamer, director of external affairs at Capability Scotland.

"When disabled people get forced into jobs, they tend to be unsuccessful jobs," Hamer said. "It can be very difficult, not just because of physical difficulties, but also mental impairments – poor mental health for example – for people to adapt to the labour market. If we start simply forcing people into jobs then there's a high likelihood that the employer won't be the best solution for them."

Hamer says that the person best placed to decide what work a disabled person can take on is that disabled person. He also says that many people who have been placed in the WRAG group should not even be there, because of serious problems with the health assessments being run by the private contractor Atos.

"The Government's own figures about these assessments is showing that they are wholly failing. The Atos healthcare regime of assessments is simply not working."

Susan Archibald, a disability rights campaigner based in Fife, branded the proposed plans "a disgrace" that "will put disabled workers at risk". Archibald questioned the DWP's commitment to making workplaces suitable for people with disabilities on work placements.

"What 'reasonable adjustments' have been put in place in, say, Tesco? Is the DWP going to stump up the money for all the things that folk with disability need? I don't think so," she said. "They are trying to say: 'We are going to enhance [disabled people's] chances of getting work.' But if you're not fit to work, something like this isn't going to enhance your chances. It'll do the opposite."

Archibald estimates that around 30,000 work-capacity assessments are being carried out each week on disability claimants by Atos. Last month, 13-year-old Kieran McArdle from Larkhall wrote to Atos saying that the assessments are "killing genuine people like my dad", after his father died of a heart attack the day after his benefits were cut. Brian McArdle had previously suffered two strokes, was unable to speak properly and was blind in one eye.

Conservative Employment Minister Mark Hoban welcomed the mandatory work placements as "a very good way to increase someone's confidence". He said that "people on sickness benefits who do all they can to improve their chances of moving back into a job have nothing to worry about", but warned that "in the small number of cases where people refuse to stick to their part of the bargain, it's only right there are consequences".

The Government runs a number of different compulsory work schemes. The largest is the Work Programme, introduced in June. Ministers said that the five-year programme would help 2.4 million unemployed people to find work.

Job seekers who have been unemployed for more than a year must complete an unpaid work experience placement, or lose their benefits. Ill or disabled peopled deemed fit to work at some point in the future will now join this group from tomorrow.

The Work Programme is being implemented by large private companies such as A4e, Ingeus and Serco, and has so far cost £435 million.

But figures released this week showed that, of the 836,000 long-term unemployed who joined the scheme across the UK, only 3.73% found work lasting 13 or more weeks.

A number of businesses, including high street retailers, and charities have taken on unpaid workers. Big names involved include Tesco, Sainsbury's, Argos, Poundland, Boots, McDonald's and Burger King.

But some have pulled out in embarrassment.

The expansion of mandatory work to include sick and disabled people will be particularly uncomfortable for disability charities involved in workfare programmes.

Scope has begun an urgent review of its involvement, and Cancer Research UK has announced that it is pulling out in the new year.


'I'm seriously considering just ending it'

Lauren Stonebanks dreamed of being a doctor. But 10 years ago, while studying medicine, she suffered a breakdown and was diagnosed with bipolar and borderline personality disorder. She has been unable to work consistently since.

"I would love to be able to work," the 33-year-old from Meadowbank in Edinburgh told the Sunday Herald. "I would love to have not been diagnosed with a mental illness, finished my medical degree, started my life as a junior doctor and carried on. But at the moment, having been ill for so long, I can barely see past next week.

Stonebanks first heard rumours about changes to the benefits system a couple of months ago on the internet, but it was only last week that she received a formal letter from the Department for Work and Pensions stating that she has been moved from income support to employment support allowance (ESA). From tomorrow, she will be eligible for mandatory work placements.

"The thought of having to do this sort of enforced workfare stuff, maybe having to work nine-to-five in Poundland or have my benefits stopped, I find absolutely petrifying," she says.

Her condition means that she is particularly vulnerable to stress. Sometimes she finds it hard to leave the house or even talk to people. Her voice quivers on the phone.

"Most days I can barely get out of bed to do the stuff I want to do," she says. Stonebanks is due to meet two friends in Edinburgh but her "anxiety is through the roof". She speaks of self-harming – and her friends fear for her.

The pressure of being forced on to a compulsory work placement is making her condition much worse: "I don't want to be here any more. I'm seriously considering just ending it. That would make life better for everyone else, because then there's one less scrounger on the system, and maybe a bit more money to go around for everyone else."

Ross Bradford was just 24 when he was diagnosed with ulcerative colitis, a painful disease of the colon that can cause constant bowel problems. He also suffers from depression.

"For someone with colitis, whose basic problem is getting to the toilet and controlling their bowels, that's a real problem," says Bradford, now 32, who lives with his mother in Glenrothes. Having been on ESA since January 2010, he is "really worried" about the prospect of being placed on a compulsory work scheme.

"My major obstacle is that I need an employer to understand that I need to be very close to a toilet at all times and have a job where I don't really move around, where I don't have responsibilities that I can't just drop, because if I need to go to the toilet, I need to go. I don't see how they would be able to find a work placement like that," he says.

Bradford, like Stonebanks, says the pressure is adversely affecting his mental health. He feels more anxious, and that in turn is contributing to his depression. He says that disability claimants are being punished to discourage others from claiming benefits.

"I don't really believe it is a scheme to get people working. It's just a scheme to do something with the annoying poor: 'We will farm them out as free labour and we will just keep putting pressure on them until they go off benefits because they can't cope with it any more.'"