June is traditionally a month of gay awareness in the US

Several hundred employees at the Department of Justice (DoJ) were expected to take part in the festivities on 18 June - but they have now been told they may not do so because President George W Bush has not officially given his sanction.

A spokesman for the gay rights organisation Human Rights Campaign, David Smith, said the decision sent a clear signal that homosexuals were not welcome at the DoJ.

"It's shameful that the federal agency that is in charge of protecting civil rights in this country is singling out one group for disparate treatment," he said.

"It sends a chilling message that gay employees are not a welcome part of the Justice Department workforce."

One DoJ Pride member, Melissa Schraibman, said arrangements for the celebrations had been finalised and the decision by Mr Ashcroft was "definitely a surprise".

'Congress venue'

Journalists have been unable to reach officials at the DoJ for comment on the decision, which breaks a tradition going back to the early 1990s.

Democratic Senator Frank Lautenberg has written to Mr Ashcroft to condemn the ban and offer to help gay employees to hold their rally at Congress.

"I find it particularly outrageous that the Department of Justice, whose mission is to ensure fairness for all Americans, would deprive its own staff members of the right to gather on public property," he said.

June is traditionally a month of gay awareness because of the 1969 Stonewall riots in New York which sparked the gay rights movement.