Fianna Fáil has begun a campaign against the introduction of a property tax, claiming it is the wrong time to do so.
The party's councillors on Dublin City Council will propose a motion opposing the tax next week, while a website is also being set up.
Party leader Micheál Martin acknowledged that a property tax was part of the agreement with the Troika.
However, he said the economy had not developed in the way expected at that time.
Mr Martin claimed there was "huge fear and anxiety about this tax", adding that the information vacuum about it was in itself damaging.
