After six years in the Joint Services Interrogation Organisation, the 35-year-old lieutenant from Newham, east London, found her sexuality subject to a military investigation.
She had until yesterday to deny the allegations or face dismissal, although she had never made a secret of her sexuality.
At the Ministry of Defence in London, she appealed to Malcolm Rifkind, Secretary of State for Defence, to lift the ban on homosexuals in the forces.
Reading an open letter to him, she said: "I appeal to you to recognise the service and sacrifice of all the lesbian and gay people who have served this country in the past and who continue to serve this country."
Military chiefs are committed to maintaining the ban on homosexuals following the recent challenge in the High Court.
The case brought by four ex-service homosexuals was dismissed unanimously, although one of the two judges, Lord Justice Brown, said the policy would eventually collapse as the European Court of Human Rights would be unlikely to uphold the MoD's arguments.
Britain and Turkey are the only Nato countries which enforce a total ban on homosexuals in the armed forces.