Another federal trial began today against the US ban on openly gay soldiers in the military.

Former Major Margaret Witt, a decorated flight nurse with 19 years of service in the Air Force and Air Force Reserves, was sacked under the law in 2007.

She kept her sexuality secret but was outed in 2004 when the ex-husband of her girlfriend informed the Air Force that she was gay.

Under the 2003 law, gay and lesbian soldiers must keep their sexual orientation secret. They face dismissal if their sexual orientation becomes known, even if outed by a third party.

Major Witt, 46, is to appear before a federal district court in Tacoma, Washington, today to argue that her rights were violated and that she should be reinstated.

Her challenge was dismissed by a federal judge several years ago but the United States Court of Appeals for the Ninth Circuit reinstated it in 2008, leading to the current case.

In recent interviews, Major Witt described how she kept colleagues from visiting her home, avoided Air Force functions and dodged questions about her personal life to keep her job.

“I want to serve my country. I have loved being in the military – my fellow airmen have been my family. I am proud of my career and want to continue doing my job,” she said.

“Wounded people never asked me about my sexual orientation. They were just glad to see me there,” she added.

If she wins her case, she will be permitted to return to her job, although the verdict will not affect other discharges under the law, known as Don’t Ask, Don’t Tell.

In court papers, the Justice Department has argued that reinstating her would undermine morale because she would be permitted to serve while being open about her sexuality, while others will not.

The department acknowledged that it was defending a law which neither the president nor the defence secretary, Robert Gates, agree with.

The Air Force argues that Major Witt has had four lesbian relationships during duty and that she is no longer qualified for her former role.

Major Witt’s lawyers say her former colleagues will testify in the case. Some are expected to say that they suspected she was a lesbian but felt that her sacking, rather than her presence, damaged morale.

Speaking to Associated Press, she revealed that the woman whose husband outed her remains her partner and that she has now come out to her parents.

“It is absolutely the best thing in my life that has come out of this,” she said.

Last week, another US federal judge ruled that the ban on gay soldiers serving openly in the military violates the US constitution.

US District Judge Virginia Phillips said she would issue an injunction barring the government from enforcing the policy.

The case was brought against the government by the Republican party’s gay group, the Log Cabin Republicans.