Those who deviate violently from the Northern peace process "will no longer be perceived to have any sort of historically legitimate purpose", the British MP, Mr Peter Temple-Morris, has said.
Mr Temple-Morris, who recently left the Conservative Party to join Labour, was addressing the Byrne-Perry Summer School in Gorey, Co Wexford.
He said such people would become "more of a `law and order problem' and can be dealt with by both governments and the administration of Northern Ireland".
Mr Temple-Morris said Sinn Fein was now "coming into the constitutional fold, repeating a theme that Ireland has seen often before, but this really could be the last act".
"For all practical purposes, Sinn Fein has accepted the Border and will co-operate in six-county government. The Ulster Unionists, for their part, appear to be modifying traditional attitudes and show signs of being ready to take the necessary risks for peace."
He spoke of the influence of right-wing unionism on the Conservative Party. He said that, following the Tory vote against the Bill allowing early prisoner releases, it looked as though the bipartisan policy on Northern Ireland was over, or at least would be operated by the Conservatives on an a la carte basis.
He was also critical of the rightwing British press which had "created great problems for the government of the day over Europe but also over any progressive policy to do with Ireland". He singled out the Daily Telegraph, the Daily Mail and the Times.