Gay rights campaigners have urged the Police Service of Northern Ireland (PSNI) to reconsider its decision to take part in New York's St Patrick's Day parade because lesbian, gay, bisexual and transgender Irish groups are barred from the march.

The city's own mayor, Bill de Blasio, has boycotted the march because of the decades-old ban on LGBT groups due to the opposition of conservative Catholic Irish Americans.

Irish cabinet minister Joan Burton also turned down an invitation to the New York parade - the world's biggest St Patrick's Day celebration – in protest at the exclusion of LGBT groups being officially represented on the march.

The veteran gay rights activist Jeff Dudgeon, who won a landmark 1981 European human rights case overturning anti-homosexual laws in Northern Ireland, said the PSNI's participation in the parade "sends a discordant symbol to the gay community in Belfast who have stood in solidarity for many years with our brothers and sisters in New York over their exclusion on St Patrick's Day."

Dudgeon added: "It is rather disheartening given the fact that de Blasio has decided not to attend, but the PSNI's need for acceptance in the States would always have taken precedence.

"In truth the police's commitment to effective responses to LGBT needs in Northern Ireland will be the measure that matters, and the jury is still out in that department although advances have been made. It is in relation to anti-gay violence that the PSNI has been found wanting in sustained, protective policing."

The Rainbow Project, a Belfast-based LGBT group, singled out Joan Burton for her refusal to attend the New York parade in solidarity with the LGBT community both in Ireland and the Irish diaspora particularly in America.

The group said: "Everyone who wishes to take part in the exclusionary St Patrick's Day parade should feel free to do so; however organisations taking part should be mindful of the fact that not all of their colleagues, friends or family members are afforded the same opportunity."

This year's parade will be the first to include officers from the PSNI in a march that at one time had as its chief marcher Joe Doherty, a Belfast IRA member who was unable to attend because he was imprisoned in New York while awaiting extradition to the UK.

Doherty was part of the IRA's "M60 gang" – named after the heavy machine gun smuggled from the United States that they used to attack police and troops in the 1970s and early 1980s.

Now, for the 2014 march, PSNI officers will parade alongside their colleagues in the Garda Síochána.

The six PSNI officers were chosen to take part in the event because of their participation in the World Police and Fire Games held in Belfast last year. The PSNI delegation will be led by a chief inspector.

PSNI Assistant Chief Constable Alistair Finlay said: "We are delighted to have six officers in New York representing the PSNI and participating in the St Patrick's Day parade."