Andrew Dismore, chairman of the House of Commons joint committee on human rights, has drafted a private member's bill designed to clarify the definition of a 'public authority' in the 1998 Act.
Campaigners from organisations such as Help the Aged and the UK Disabled People's Council say a court case in 2002, involving the closure of a care home run by disability charity Leonard Cheshire, has led to the exclusion of some voluntary and private sector organisations - particularly those that run residential homes - from the definition of a public authority.
This, they say, leaves vulnerable people open to human rights abuses.
"We're certainly aware that disabled people's human rights are being violated," said Simone Aspis, development officer at the UKDPC.
Dismore wants to amend the act so that services contracted out by local authorities also come under the public authority umbrella.
"Many services previously delivered by public authorities have been privatised or contracted out to private suppliers, but the law has failed to adapt to that reality," he said.
However, Dismore's bill, which is due to have its second reading on 15 June, has also attracted some criticism from the sector.
Campaign group Liberty said the loophole should be tackled through case law, not through a blanket amendment of the act. "Clarifying the definition of a public authority to provide human rights protection is very important," said Anna Fairclough, legal officer at Liberty. "But it is best determined case by case."