Dublin City Council is to get legal advice after a development company refused to give assurances that it will not demolish buildings around Moore St pending their assessment as protected structures.

The dispute concerns five buildings on Moore St and surrounding lanes which city councillors voted to list as protected buildings. This would be in addition to numbers 14 to 17 Moore St, which are protected as a national monument.

However Hammersons, the company now in control of the site stated in a letter to the city council's CEO Owen Keegan that it could not undertake not to demolish as this would interfere with the planning permission for the site.

The buildings in question are numbers 10, 20 and 21 Moore St as well as three buildings in laneways to the rear known as the White Cottage, O'Brien Mineral Water Works and the Bottling Stores.

Hammersons, which owns Dundrum Town Centre, has permission valid until 2022 for a large retail development known as Dublin Central stretching from Moore St to O'Connell St.

It also so far failed to allow access to the city council for an assessment that is required before a property can be listed as a protected structure.

In the latest letter to the city council, Edward Dobbs of Hammersons threatened legal action on behalf of the project company Dublin Central Limited Partnership (DCLP) if the protection status is proceeded with.

He says this would be in conflict with the law as there is planning permission in existence for the site.

"The proposed course of action would be considered to be an oblique attack on the permission. As you will understand, should it be progressed, DCLP would be compelled to take the necessary step to protect our constitutional and property rights" he said.

Following this council chief executive Owen Keegan stated in a letter to councillors that he proposes to get legal advice on how to proceed.

The High Court ordered that the entire terrace and surrounding lanes should be declared protected structures but this is under appeal.

Dublin Lord Mayor Mícheál Mac Donncha said Hammersons need to recognise that regardless of the outcome of the court case the existing planning permission is "inoperable".

He said "the company needs to come up with a new plan to deliver a historic quarter with a battlefield site along with retail and commercial development".