The Tanaiste has said the Nice Treaty will not adversely affect Ireland's tax system.
Speaking to her party - the Progressive Democrats - at the general council Mary Harney said 'no' campaigners were promoting a lie campaign.
She said the national system of taxing would not be replaced by a harmonised EU system.
She argued her party was always vigilant about protecting Ireland's tax regime and that was why her party was promoting a 'yes' vote.
Mary Harney insists that if the public want low taxes then they should vote 'yes'.
In addition, the Tanaiste says the 'no' campaigners are openly hostile to the international investors who support 150,000 jobs directly in Ireland.