The oath of loyalty that must be taken by Westminster MPs should be amended to reflect the aspirations of Irish citizens elected to represent Northern Ireland, according to Michael McDowell.
The Minister for Justice was speaking after a meeting with the Ulster Unionist Party in Dublin yesterday.
Mr McDowell met the delegation, led by Sir Reg Empey, in his capacity as president of the Progressive Democrats.
He criticised recent suggestions from Sinn Féin that Northern Ireland MPs should be able to abstain from Westminster and participate instead in Dáil Éireann.
This would run contrary to the clear purpose of the Good Friday agreement, he said, which was that North-South parliamentary relations should be conducted on the basis of equality in a joint parliamentary forum.
However, he added that there was a "very strong case" for amending the oath at Westminster to fully reflect "the solemn obligation of the UK government under Article 1 of the British-Irish Agreement in respect of the rights, nationality, aspirations and identity of Irish persons elected to represent Northern Ireland in the UK parliament".
He said Sinn Féin members used the oath to justify their refusal to participate in Westminster. "It is a pretext that could be dispensed with. Would they then participate? I doubt it. But amending the statement of admission to Westminster to make it compatible with Irish citizenship would remove the fig leaf."
Referring to the recent loyalist violence in the North, and the part played by the Orange Order, he said he fully supported the position of Sir Hugh Orde, the PSNI Chief Constable, that those who organised parades, and made statements about their routing, had to take responsibility for the consequences.
He described the violence of the past few days as "disastrous", pointing out that scenes of ferocity were broadcast across the world and would do great economic damage, deterring inward investment.