The US Marines’ top general has said that lifting the ban on out gay soldiers could cost lives.

General James Amos, commandant of the Marine Corps, says a Pentagon study on lifting the ban showed that front-line troops were most concerned about serving alongside out gay colleagues.

He said that gay servicemembers might cause a “distraction” that could result in increased injuries and deaths.

Gen Amos told reporters at the Pentagon: “When your life hangs on a line, on the intuitive behavior of the young man … who sits to your right and your left, you don’t want anything distracting you.

“I don’t want to lose any Marines to distraction. I don’t want to have any Marines that I’m visiting at Bethesda [hospital] with no legs,” he said.

“When your life hangs on the line,” he said, “you don’t want anything distracting. . . . Mistakes and inattention or distractions cost Marines’ lives. That’s the currency of this fight.”

He has opposed lifting the ban before but according to the Washington Post, this is the first time a senior officer has suggested that troops could be seriously injured or killed if gay soldiers can serve openly.

The pro-repeal Servicemembers Legal Defense Network accused him of “fear tactics” and said he should resign.

Army veteran and executive director Aubrey Sarvis said: “General Amos needs to fall in line and salute or resign now. He implied that repeal will lead to Marines losing their legs in combat.

“Those fear tactics are not in the interest of any service member. The General’s goal is to kill repeal no matter the consequences, perhaps at the dereliction of his other duties.

“He had his say before the Senate and House. General Amos needs to stop lobbying against his Commander-in-Chief, the Secretary of Defense, and the Chairman of the Joint Chiefs. If he cannot do that, the President should ask for his resignation.”

The Pentagon survey found that most troops were relaxed about lifting the ban.

However, nearly 60 per cent of troops in the most dangerous roles – in the Marines and combat units – said repeal would be damaging.

In October, the the retiring commandant of the Marine Corps said that almost all Marines would be unhappy about serving with out gay colleagues.

Gen James Conway said that “90 to 95 per cent of the Marines” he had informally surveyed said they had concerns about the consequences of allowing gay men and lesbians to serve openly.