A group of married gay and lesbian troops are suing the US federal government for denying them the recognition, benefits and family support granted to heterosexual service members.

The lawsuit was filed today in Boston and says the federal government, through the Defence of Marriage Act, violates their constitutional rights.

Under the law, the Pentagon must treat gay troops as unmarried, even if they are in legally-recognised marriages.

They are being represented by the Servicemembers Legal Defence Network, which says gay troops make the same sacrifices as heterosexual counterparts – but are treated unfairly.

Army veteran and SLDN executive director Aubrey Sarvis said: “This case is about one thing, plain and simple. It’s about justice for gay and lesbian service members and their families in our armed forces rendering the same military service, making the same sacrifices, and taking the same risks to keep our nation secure at home and abroad.

He added: “These couples are in long-term, committed, and legally recognised marriages and the military should not be forced to turn its back on them because the federal government refuses to recognise their families.”

Lead plaintiff Major Shannon McLaughlin of the Massachusetts National Guard, who is married with ten-month old twin girls, said: “We’ve been serving our country too long, working too hard, and sacrificing too much to see our families denied the same recognition, support and benefits as our straight, married counterparts.”

Those named in the lawsuit as defendants are the Secretary of Defence, the US Attorney General and the Secretary of Veterans’ Affairs.