A Sinn Fein MP has sparked controversy at the Conservative Party conference by telling delegates he did not regret the Brighton bombing.
The bombing of the Grand Hotel killed five people
Conor Murphy said the 1984 bombing of the Tory conference which left five people dead was "part of a war".
He said his only regret was that people had been driven to violence.
David Burnside, UUP, told Mr Murphy to "lower his head". Shadow NI secretary David Lidington said it showed how far republicans "still had to travel".
Mr Murphy made the comments at a fringe meeting in Blackpool, almost 21 years after the IRA blew up the Grand Hotel in Brighton. The prime minister at the time, Margaret Thatcher, had a narrow escape.
Asked if he regretted the bombing, Mr Murphy said: "At the time I certainly did not regret it, I will be honest with you. I think it was part of a war, which was a very difficult war between the people of the island of Ireland.
"I regret that it came to a situation where people felt they had to take on violence in order to pursue their political ends."
Mr Murphy, the MP for Newry and Armagh, was the first member of his party to take part in a debate during a Conservative conference.
His comments were condemned by opponents.
Ulster Unionist assembly member David Burnside, who was in the Grand Hotel in Brighton at the time of the bombing, was outraged.
He told Mr Murphy: "You blew up the centre of the democratic movement in the UK, the elected government of this country, and you have no remorse or regret that these murders were carried out and you should lower your head."
Shadow Northern Ireland secretary David Lidington said later: "These comments show the distance republicans still have to travel. Whatever grievance republicans have had in the past that does not justify taking a single human life.
"The thing that now would demonstrate they have put that terrorist past behind them would be a clear endorsement of the rule of law and the authority of the police. That they have yet to do."
Patrick Magee was later convicted of planting the bomb which ripped through the hotel in the early hours of 12 October 1984.
The five people killed in the bombing were Sir Anthony Berry, 59, the MP for Enfield Southgate; Roberta Wakeham, 45, wife of the then Tory Chief Whip Lord Wakeham; The Tories' North West Area Chairman Eric Taylor, 54; Muriel Maclean, 54, wife of Scottish Chairman Sir Donald Maclean; and Jeanne Shattock, 52, wife of the Western Area chairman.
One of the best-remembered images of the night was that of the former Secretary of State for Trade and Industry, Norman Tebbit, who had to be rescued from the rubble. His wife was paralysed in the blast.