A trust connected to the trade union Unite applied to be exempted from social housing for a development at its former headquarters on Merrion Square in Dublin while one of its top officials was planning the occupation of Apollo House in the city centre last month.

Unite's application for a Social Housing Exemption Cert was granted by Dublin City Council on 16 December, the day after its official Brendan Ogle gained access to Apollo House to begin a four-week occupation by homeless people and volunteers.

A group called Hands Off The Homeless, which held a demonstration outside the building, have reacted angrily to news it was lying empty during the occupation of Apollo House.

Spokesman Vincent O'Hanlon said Apollo House had been chosen as a "publicity stunt" when the Merrion Square building could have been used to house the homeless without fear of eviction.

The exemption application was made by a company called 'Unite the Union Trustee Company', which like the union itself, is based in London.

This company is listed on the Standards in Public Office Commission register for 2016 as one of two trustee companies of the Unite union in Ireland.

All new developments are required to provide 10% social or affordable housing under Part V of the Planning and Development Act 2000.

There are exemptions for small-scale developments and building conversions, but the proposed developer has to apply to the local authority for an exemption.

The Unite trustee company applied for the exemption on 7 December.

This evening. the union said it will withdraw its application to be exempted from social housing in the development of its Merrion Square building if "it is not appropiate to the process".

Regional secretary Jimmy Kelly defended the application for private residential development at the former union headquarters.

"The planning permission is based on arrangements within the building and what would make it more attractive to be sold," he said.

Mr Kelly said the union has surplus property and that selling the property would make finance available to union members and the campaigns they want to run.

"The members deserve that we manage the union in their best interests and that was what was done".

But he said the union was not trying to get out from any commitment to social housing and if the application is not compliant it will be withdrawn immediately.

He said the union will continue to provide support to the campaign against homelessness.

He defended the occupation of Apollo House rather than opening the Merrion Square building for the homeless. He said the campaign involved targeting NAMA property and there was never a question of targeting union property.

Unite's former headquarters at 15 Merrion Square North has been empty for nearly three years and was previously on the market in 2012 for an estimated €2m.

It is believed to have toilet and shower facilities.

It has had a complicated planning history but the latest application is to convert the original five-storey protected Georgian structure into a single dwelling and to build a five-storey apartment block at the rear with three three-bed and one one-bed apartments.

A top floor flat in another address on Merrion Square sold for €300,000 in 2014.