People with learning disabilities are more likely to be detained under mental health laws, more likely to end up in an institution and likely to be there for longer than other people, according to campaigners, who want a review of the system.

The charity Enable Scotland is calling on MSPs to support an amendment to the Mental Health (Scotland) Bill, which reaches stage three at Holyrood on Wednesday.

Tabled by Jackie Baillie MSP, the amendment would insert a binding commitment to review the position of people who have learning disabilities, under the Mental Health Act.

Enable says that people with learning disabilities have bene promised a review for over a decade, but are still waiting. Many believe they should not be subject to mental health legislation and the parliament's

Cross Party Group on Learning Disability has also expressed collective concern that people with learning disabilities are not always well served by Mental Health Legislation.

The group concluded they are disproportionately subject to compulsory measures under the act; and considerably more likely to spend more time in an institutional setting than people without a learning disability subject to the current Act.

However some fear removing people with learning disabilities from the Mental Health Act would leave gaps in legislation, with the result that people with learning disabilities become more vulnerable.

Jan Savage, Assistant Director of Campaigns and Membership at ENABLE Scotland, and Secretariat of the Cross Party Group on Learning Disability said a review was clearly necessary and had first been promied in 2001. "We consider it unacceptable that such a review has not happened before now, given the earlier recommendations in 2001 and 2009. MSPs now have the opportunity to deliver a firm legislative commitment and secure the long-promised review."

She added: "The amendment tabled by Jackie Baillie MSP seeks only to secure a review of the position of people who have learning disabilities under the Mental Health Act. The amendment does not pre-determine the outcome of the review."