The US Senate yesterday blocked legislation to end the ban on out gay troops.

Senators voted 57-40 – three votes short of the 60 needed – to pass military funding legislation which included a repeal measure.

The vote means it is unlikely the controversial law will be overturned this year.

Republicans had promised to block all bills other than those to fund the government in a row over expiring tax cuts.

President Barack Obama, who promised two years ago he would end the ban, criticised a “minority of senators” for voting against the legislation because they oppose repeal.

“While today’s vote was disappointing, it must not be the end of our efforts,” he said.

“This law weakens our national security, diminishes our military readiness, and violates fundamental American principles of fairness, integrity and equality.”

The 1993 law allows gay and lesbian troops to serve in the military so long as they keep their sexuality secret.

Also known as Don’t Ask, Don’t Tell, it bans superiors from asking troops whether they are gay but they can still be fired if their sexuality becomes known.

One Republican voted to pass the legislation – Susan Collins of Maine. She said after the vote that she and independent Senator Joe Lieberman would jointly introduce a separate bill to end the ban.

Ms Collins said a standalone bill would be more likely to garner the necessary support.

However, their bill would have to be passed by the House and may run out of time before the Republicans become stronger in the Senate in the next session.

Aubrey Sarvis, of the Servicemembers Legal Defense Network, said another way to repeal the ban must be found.

He said: “The Senate and the president must remain in session and in Washington to find another path for repeal to get done in the lame-duck.

“While difficult, realistic options still exist for advocates and Senators to move repeal this year. We need to keep pushing as the Senate is scheduled to break for holiday vacation.

“We implore all who support repeal to join us outside the Senate this Friday. As secretary of defence Robert Gates said, ‘If not now, when?’.”

The group plans to hold a rally today on Capitol Hill to protest at the vote.

A Pentagon report released at the beginning of this month said that the ban can be lifted safely without too much disruption.