US service members are allowed to march in uniform in a gay pride parade for the first time in U.S. history.

The US department of defence will allow active duty members of all branches of the military to don their service uniforms while marching in an upcoming San Diego gay pride parade.

The move, confirmed in an internal defence memo, marks the first time the military has granted such blanket permission since the September repeal of the “Don’t Ask, Don’t Tell” policy, under which gay individuals were allowed to serve in the military only if they did not divulge their sexual orientation.

“It is our understanding that event organisers plan to have a portion of the parade dedicated to military members,” Rene Bardorf, the deputy assistant secretary of defence for community and public Outreach, wrote in an internal memo.

Citing national media attention to the issue, Bardorf granted approval for service members to participate, but limited that approval in scope to the 2012 San Diego Pride Parade.

“We further understand organisers are encouraging service members to seek their commander’s approval to march in uniform and to display their pride,” Bardorf wrote.

Nearly 400 military members have already signed up to march in the parade, according to organiser San Diego LGBT Pride.

Many more are expected to participate in the military parade after the announcement went public, Fernando Lopez, the director of public affairs for San Diego LGBT Pride, told Reuters.

Changing opinion

In the past, only armed services veterans, not those on active duty, were allowed to wear their uniforms at gay pride parades.

Commanders could give permission to individuals to take part in such events in uniform but no blanket permission had previously been issued, Lopez said.

In a second internal memo published on Thursday, Bardorf said that for parades other than the San Diego event for which he issued a specific memo, local commanders are given discretion in allowing service members to participate unless it is “likely to garner national or international interest or news coverage.”

The approval for active service members of the Army, Marine Corps, Navy and Air Force to participate in the gay pride parade in uniform is the latest of a string of milestones following the repeal of “Don’t Ask, Don’t Tell.”

Under the policy, more than 14,500 US service members removed from the military since the rule went into effect in 1993, according to the Service members Legal Defence Network.

The end of the policy has come at a time of steadily increasing public support for same-sex marriage. The Gallup polling organisation’s recent survey says that half of American adults are now in favor of gay marriage.