The future nature of Belfast Zoo is uncertain after a motion was tabled by a city councillor to phase out the display of caged animals and return the animals "to their natural habitats". However, the motion also envisaged transforming the zoo into a "world-class visitor attraction by 2025".

Councillor Conor Maskey of Sinn Fein put forward the motion at a Belfast City Council meeting held on Monday 3 February. It proposed that the zoo should instead become a conservation centre for indigenous animals and gave a commitment to secure all existing jobs.

Reported in the Belfast Telegraph, the statement went on: "The ratepayers of this city have to subsidise the zoo to the sum of £2.5m (US$3.2m, €3m) per year. The savings from the zoo site could provide substantial funding for the much-needed regeneration of the city, create jobs and opportunities, and attract more visitors.

"The five-year transitional period will enable the council to safely return animals to their natural habitats in a carefully crafted phased approach."

However, there was criticism of the motion from rival political groups on the city council, as well as from trades unions and animal welfare bodies. Among the more than 600 animals kept at Belfast Zoo is a pride of Barbary Lions, which no longer exist in the wild.

Councillor George Dorrian of the DUP said that while he was concerned that the zoo was loss-making, it required more investment and the creation of a wider outdoor activity leisure park to enhance it.

"We cannot support this Sinn Fein proposal to, effectively, close the zoo. The statement by Sinn Fein is a gross misrepresentation, writing about 'caged animals', and lacks reality by proposing to 'return animals to their natural habitats'.

"It fails to recognise the important role of Belfast Zoo in education and in international breeding programmes for both indigenous and rare and endangered species."

A statement from The European Association of Zoos and Aquaria, reported by ITV News, referred to Belfast Zoo's "impressive" record on conservation, and said that reintroducing the animals to the wild would result in "unavoidably high" mortality rates – perhaps up to 70 per cent. It added that the Sinn Fein plans showed "no understanding of these principles and outline no intention of engaging with experts in the field".

In response to these reactions, Councillor Maskey said: "This was never about closing the zoo, it was about properly investing in the site to ensure we are in keeping with a modern and ethical approach to the city and the animals and don't burden the ratepayer."

He added, however, that the party would discuss amending the motion before it is referred to the Strategic Policy and Resources Committee later this month.