Tánaiste Ms Mary Harney said today a Yes vote in the Nice Treaty was a vote for "peace, stability and prosperity in Ireland and Europe".
Speaking at the launch of the Progressive Democrats campaign for a Yes vote, Ms Harney, said she was confident the referendum would be passed by the Irish people. But she expressed concern about the "high level of apathy among voters in things European".
The Tánaiste said she would be "very embarrassed as an Irish person" if the referendum was rejected.
She said a Yes vote was in the national interest and that a rejection would most certainly diminish Ireland’s international position.
Ms Harney said it was important for Irish people to show solidarity, generosity and friendship to countries seeking to join the EU.
The projected rise of the European single market to 500 million people would be "good for trade, good for jobs and good for Ireland", she said.
The Workers' Party, opposing the treaty, has said it is entirely possible to achieve a No vote in the referendum.
Party president Mr Seán Garland said at his party's No vote launch: "If this treaty is ratified by the Irish people it will be possible for large states such as Germany and France, combined with any third member state, to block any decision which they consider unfavourable to them."