The two parties tried on Thursday to force the ACT government to reverse its decision on the future of the historic Kingston Foreshore building, which has been earmarked as the new home for Megalo.

But Arts Minister Joy Burch said yesterday that she was not bound by the Assembly motion passed by the other two parties, urging the government to act on the findings of a multi-party committee that recommended the workshop be converted to a ''multi-use'' venue.

Canberra's arts community remains bitterly divided over the future of the workshop since the building was ''discovered'' to be a ''unique musical space'', when it was used for performances in the Canberra International Music Festival between 2009 and 2011, despite a deal having already been agreed to move Megalo into the building.

The Liberals and Greens moved their motion on Thursday as about 40 choristers from around the city protested outside the Assembly against the government's refusal to budge from its original decision.

Megalo creative director Alison Alder said yesterday her organisation was dismayed by the actions of the Greens and the Liberals.

''The Megalo board, staff and members were disappointed in the proceedings and vote by the coalition of Liberals and Greens in the ACT Legislative Assembly last night,'' Ms Alder said.

''Sadly, they seem unable to recognise and in good spirit, abide by the normal conventions of responsible government in a democracy.

''Megalo supports the words of Minister Burch in the Assembly, which made it clear that the government recognises the opportunity that Megalo in the Fitters Workshop will provide for the ACT, building the Kingston Arts Precinct as a hub of national excellence.''

Ms Alder reiterated her argument that using the building once again as a functioning workshop would ensure that it was in use all-year-round.

''The government has made a positive decision to put a heritage workshop to work again 52 weeks a year,'' she said.

''Megalo has stated many times over why it is the best fit for the Fitters Workshop and all we can add is to yet again emphasise that Megalo is a community organisation with strong community support.''

Meantime, Assembly Speaker Shane Rattenbury confirmed that Thursday's motion was not legally binding on Ms Burch but the Speaker warned it still left her with a political problem.

''But at the end of the day, even without legal power, the Assembly does have considerable persuasive power,'' Mr Rattenbury said.

''The Assembly has power in guiding the executive and may even withdraw its confidence in the executive. So though it has no legal effect, it's a political discussion because the government can ignore the motion if it wishes but the consequences then become political consequences, potentially.''

Ms Burch dismissed the move by the Greens and Liberals as a ''political stunt''.

''What we saw this week was a political stunt by the opposition and Greens,'' Ms Burch said.

''[It] has achieved nothing other than continue to divide Canberra's arts community and trample on Megalo Print Studio's plans and accommodation needs.''