A plan to rezone industrial sites in Dublin city to provide land for 20,000 housing units has suffered another setback following a legal challenge.

City councillors have been given legal advice that a High Court action against one of the rezonings at Chapelizod could succeed.

Pat O'Donnell and Company a plant machinery facility which owns part of the 3.6 hectare site on the Chapelizod Bypass/Kylemore Road has claimed his company was not "fully heard" in relation to the rezoning.

The vote by councillors changed the sites zoning from from Z6 industrial to Z10 mixed use which includes residential.

Lawyers have also argued that the company had to move from a previous site after complaints from residents about noise and the company is concerned that the same issue will arise at this site.

In a letter to councillors the city council's chief executive Owen Keegan said legal advice is that the action is "more likely than not" to succeed.

In his opinion councillors should rescind the rezoning and revisit the site in relation to the 2022 Development Plan.

It will be debated at a monthly meeting next Monday.

Independent councillor Mannix Flynn said the whole plan for rezoning industrial sites around the city could now "unravel".

"Where was the good, solid legal advice? The council always knew they were on thin ground and this was rushed. The chief executive has to hold his hand up and admit an error. It is just not good enough".

The Chapelizod site was one of 20 sites to be rezoned as part of an initial phase that would free up land for 3,500 homes.

However, this plan was heavily criticised at a special meeting of councillors and it was scaled back to rezonings for just 1,575 units.

Concerns were expressed by councillors that most of the sites would be Strategic Housing Developments meaning that the council would not have any control.

Two rezonings in Santry comprising sites with a potential for 1,200 homes were withdrawn after a large amount of objections from local residents during public consultation.

The Chapelizod site was one of four rezonings - along with land in Coolock, Drimnagh and Crumlin - that were changed to mixed use instead of purely residential to protect existing employment.

And the Chapelizod rezoning was tied in a vote by councillors and only went through on the Lord Mayor's casting vote.

Another large site in East Wall was already withdrawn from the proposals as the Office of the Planning Regulator had pointed out that the land would be needed for a future Eastern Bypass.

And a proposal to rezone a site at the Greenmount Indstrial, Harolds Cross was defeated when voted on.

Another rezoning at Wolfe Tone Quay was passed but had no potential for housing. 

The fifteen remaining sites for housing were in Finglas, Artane, Harmonstown, Chapelizod, Inchicore, Fairview, Kilmainham, the Liberties, Drimnagh, Dolphin's Barn, Crumlin, Harold's Cross as well as lands near Connolly Station.

Chief executive Owen Keegan told the meeting that these sites are the "least problematic" compared to larger land parcels.

If the bigger sites in Finglas, Glasnevin, Coolock and Naas Road are rezoned the scheme could provide up to 20,000 homes in 20 years time.