The Sinn Fein president, Gerry Adams, has told an Oireachtas committee that Northern nationalists who have elected their representatives as Irish legislators have the right to send them to the Dail and Seanad.
He suggested to the Oireachtas Committee on the Constitution that all Northern Ireland's Westminster MPs should have the right to attend and speak in the Dail as "consultative members" pending "the right of all representatives to full voting rights".
He also wanted the Northern electorate to have the right to vote in Irish referendums and presidential elections. This would require a constitutional amendment, he said, while granting consultative rights would be an internal matter for the Dail.
"Unionist seats could be left vacant as a constant assertion of the recognition of the Irish nation that they have a right of entitlement in our institutions."
For the SDLP, Mr Denis Haughey suggested that the Seanad electorate could be extended to form a Northern "electoral college", made up of the North's MEPs, Assembly members and the 600 members of the North's local councils.
A fixed number of senators could be nominated from the North, separate from the Taoiseach's list. There could also be a "right of hearing" before the Dail, Seanad and Oireachtas committees for members of the Northern Ireland Assembly.
Mr Alban Maginness said the right for Northerners to vote in Irish presidential elections would be another "highly symbolic" move, although he recognised the practical difficulties involved. It would require the British government's full co-operation.