Sinn Féin leader Gerry Adams has confirmed that his party's four MPs will not take their seats in Westminster to vote against Britain leaving the EU.
Labour's finance spokeswoman Joan Burton asked in the Dáil if Taoiseach Enda Kenny had discussed the issue with the North's Deputy First Minister Martin McGuinness and if Sinn Féin MPs would "vote in favour of the interests of the whole island of Ireland".
But Mr Adams firmly ruled it out.
“We were elected – and it was my great honour to represent the people of Belfast for a long time – to not take our seats in the British parliament,” he said.
“It is a foreign parliament. It is not our parliament and we owe no allegiance to the English queen. We wish her well and we wish the people of Britain well.”
Mr Kenny said Mr Adams had answered that question, but agreed with Ms Burton, and with Green Party leader Eamon Ryan, that "the situation is unprecedented".
National jersey
During sharp exchanges, Fianna Fáil leader Micheál Martin said Sinn Féin’s approach was a “curious form of abstentionism because they have never abstained from taking the salaries or the expenses from Westminster or the Saxon shilling”, which he estimated at “a couple million over a couple of years”.
He added that a principled form of abstention would be to abstain altogether.
But Mr Adams said Mr Martin “would be an expert on principles”.
When the Fianna Fáil leader described the move as “an extraordinary sort of hypocrisy”, Mr Adams said “you should look in the mirror”.
Mr Martin said: “We dealt with abstentionism in 1927 in the second election.”
Mr Adams replied: “What about confidence and supply?”
Earlier, Taoiseach Enda Kenny said Brexit is a "national challenge for everybody" and it should be led by him and his department and not "a Minister for this or a Minister for that".
He said the Dáil could discuss the issue every week for up to two hours. Everyone should be “fully briefed because everybody has to wear the national jersey here”, he said.