A bill has been introduced to allow gay and lesbian servicemembers the right to immunity when appearing before congress to give evidence on the current military gay ban.

Florida Democrat Alcee Hastings, who introduced the legislation, said that if congress debates lifting the ban next year, gay and lesbian soldiers must be able to speak openly at hearings without the risk of losing their jobs.

The gay ban, also known as ‘don’t ask, don’t tell’ was introduced in 1993. It allows gays and lesbians to serve in the US military as long as they keep their sexual orientation secret. Around 13,000 servicemembers have been dismissed since it came into force.

Hastings told Associated Press: “How can there be anything more important than a gay member of the service having the right to testify before the Armed Services Committee of the Congress that he is under the aegis of?

“But if they come and testify, that testimony could be used against them under ‘don’t ask, don’t tell.’ In my judgement, it’s just a question of fairness.”

Hearings on ‘don’t ask, don’t tell’ that were promised by the end of this year have been postponed and are now expected in early 2010.

The Palm Centre, which has carried out much research on the ban, said the move is seen as a “carve-out” because it would drop a section of the gay ban legislation.

Senior research fellow at the institute Dr Nathaniel Frank said: “When the House and Senate evaluate the effectiveness of ‘don’t ask, don’t tell’ next year, they will need to hear from those most affected by the law.

“If current gay troops are not allowed to testify honestly, the quality of deliberations will suffer.”

The bill would provide protection from dismissal and retaliatory personnel actions for any servicemember, gay or straight, who speaks for or against the ban.

President Barack Obama and his defence secretary Robert Gates have said they are seeking ways to relax the prohibition. Obama has promised to repeal it but has told gay activists he needs more time.

Several recent initiatives to soften or suspend the ban include a moratorium proposed by Senator Kirsten Gillibrand as well as a proposal by Hastings to de-fund the implementation of the ban. These were both blocked by congress and the White House.