After years of rights group fighting the law, the ban against gays serving openly in the U.S. military, usually known as thee "Don't ask, don't tell" policy has finally been repealed, ending a policy under which more than 14,000 men and women were discharged.

From Tuesday 20 September, gay service members cannot be discriminated against for their sexual identity, but the change comes after an 18 year-fight to remove the discriminatory policy.

To mark the end of the "Don't ask, don't tell" policy, the U.S. army sent a memo to soldiers explaining "From this day forward, gay and lesbian soldiers may serve in our Army with the dignity and respect they deserve."

"We expect all personnel to follow our values by implementing the repeal fully, fairly and in accordance with policy guidance," the memo obtained by The Washington Post said. "It is the duty of all personnel to treat each other with dignity and respect, while maintaining good order and discipline throughout our ranks. Doing so, will help the U.S. Army remain the strength of the nation."

U.S. Defence Secretary Leon Panetta and Joint Chiefs of Staff Chairman Mike Mullen, are now expected to discuss the change, which took effect at 12:01 a.m. EDT, at a Pentagon news the move was welcome by rights groups and activists, including soldiers who have directly been discharged as a result of the rule, and celebratory event are now being organised across the U.S.

"Don't ask, don't tell" started in 1993, after President Bill Clinton did not manage to end a ban on gays serving in the military, as he faced strong opposition from the Joint Chiefs of Staff and members of Congress.

The debate was later used by President Barack Obama who promised to seek an end to the policy during his presidential campaign.

The final change in policy came after President Barack Obama signed legislation that brought an end to the ban on openly gay men and women serving in the armed forces in December 2010 at the Department of Interior with officials such as Vice President Joe Biden, House Speaker Nancy Pelosi, D-California, and Senate Majority Leader Harry Reid, D-Nevada, in attendance.

The ban of the law will still stir up controversy throughout the U.S. as some still stand by the "Don't ask policy" which explained that the presence of openly gay service members "would create an unacceptable risk to the high standards of morale, good order and discipline, and unit cohesion that are the essence of military capability."

Most of the people who supported the law and opposed the ban claimed that shifting the policy could have disastrous consequences on the military institution as pushing forward a liberal agenda in the army would only prevent it from fulfilling its role.

With brand names going from GI Jo to Hollywood movies depicting American soldiers as hard-working, highly efficient, willing to sacrifice for the good but also in most cases heterosexual and upholding conservative family values, pro-law activists saw it as an assurance that moral values would dominate the institution.

Talking about the end of the ban, U.S. Rep. Barney Frank, D-Mass., told Politico that the "important thing about this date is two or three years from now, when none of the negative predictions come true".

As a result of the shift, the OutServe advocacy group set up an online poll of 533 people which revealed that 39 per cent of gays and lesbians in active service planned to come out to some people in the military.

Nearly 17 per cent said they intend to reveal their sexuality to a few close friends in their units, 9 per cent said they would disclose it to most of the people in their units and 13.5 per cent said they would make it known to everyone but a third said would not make their sexuality known to anyone who didn't already know about it, the sampling indicated.

Despite the law being repealed, years of discriminations may have instilled fear into those considering revealing their sexual preference, it will take time for gay and lesbians to feel confident about opening up to their fellow service men on that level without fearing to be marginalised, "shunned" or discriminated against.