People with disabilities who are working in sheltered employment are largely underpaid, according to a recent poll by the Lien Centre for Social Innovation.

Full-time employment in sheltered workshops drew a median monthly pay of $200 to $499.

"It does not even match the industry standard for, say, a cleaner or packer. This is much lower than that," lead researcher Ranjana Raghunathan said.

"Some respondents liken what they earn at a sheltered workshop to an allowance, rather than a salary, highlighting the meagre pay," she added.

Sheltered employment programmes are run by charities and offer jobs that tend to be low-skilled, such as data entry and telemarketing.

The survey polled 100 physically disabled people aged 20 to 59, of whom 46 were in sheltered employment. The rest were in mainstream employment, unemployed or students.

More than half of the 46 said their salaries were low and insufficient to meet their needs, such as living expenses and healthcare costs.

Besides proposing higher wages, some respondents also suggested that there be more opportunities to acquire marketable skills while in sheltered employment.

The model of sheltered employment is increasingly unpopular in developed countries.

Critics argue that it further isolates people with disabilities, and does not teach skills that prepare them for integration into open employment.

But until mainstream employment is more inclusive, it may be important to still have sheltered workshops, said Ms Raghunathan.

At SPD, which represents people with disabilities, some clients who have limited functional abilities earn up to $690 a month, including transport subsidies.

But craftsmen, who are more skilled and make products such as photo frames by hand, can earn an average of $1,300 a month, including transport subsidies.

SPD executive director Abhimanyau Pal said: "The challenge is in securing enough contract work, and work that pays us better. We hope organisations will be more forthcoming in engaging services offered by our sheltered workshop.

"Only with more contract jobs or work that brings in higher revenue, are we then able to offer more allowance for the clients."