Amnesty International is calling for a Ride With Pride bus to celebrate the lesbian, gay, bisexual and trans community.
As the Belfast Pride parade gets under way today, Amnesty director Patrick Corrigan says Translink should be following the lead of Transport for London (TfL).
Its new Routemaster bus was dressed in Ride with Pride LGBT livery to mark the 10th anniversary of the TfL LGBT staff network being launched.
Mr Corrigan said: "It is great to see an iconic bus, designed and built by Wright Bus in Northern Ireland, being used to fly the rainbow flag for LGBT equality.
"Translink should take inspiration from Transport for London and commission a similar design to celebrate the 25th anniversary of Belfast Pride this summer.
"A Ride With Pride Metro bus would send a powerful message, to residents and visitors alike that Belfast is a great city that wants to celebrate diversity and equality for all."