The draft Mental Incapacity Bill risks damaging the rights of those it seeks to protect, the joint parliamentary committee considering the bill heard last week.

Jean Collins, director of learning difficulties charity Values Into Action, told the committee that the proposal for a "general authority" could make the situation for people with mental incapacity "far worse than it is now". Under the authority one person would be given the power to make decisions for someone with a mental incapacity.

Collins said she would prefer the bill to make it compulsory that a person with a mental incapacity should have at least two, and preferably three, other people supporting them and helping them to make their own decisions. These people could include a family member, a friend and a social worker, she added.

"There are many more dangers when just one other person is involved," she warned. "If there are two or three, they police one another."

West Sussex director of social services and chairperson of the Association of Directors of Social Services disability committee John Dixon echoed the potential problem of others being allowed to make the decisions for those with mental capacity problems.

"We, the social workers, would not presume to speak for people who have mental impairments, and we think that lawyers and others should not do so either," he told the committee at an earlier hearing.

Dixon added that he would like the bill to guarantee people with a mental incapacity the right to an independent advocate, whose role would be to make sure that those for whom they acted had their say.

The committee will report on the draft bill to parliament by the end of November.