It is one of Sinn Féin's recurring demands that Northern Ireland MPs be allowed to speak in the Oireachtas. Having Sinn Féin MPs in Leinster House would achieve the key symbolism of turning Dáil Éireann from what they used to call the "Free State parliament" into a de facto, even if not actually de jure, all-Ireland Dáil. It would also benefit Sinn Féin electorally.
Even members of Sinn Féin privately admit that their TDs, whatever about their clientilist abilities, are mediocre as legislators and as the public face of the party.
Send the big guns of Gerry Adams MP, Martin McGuinness MP and others into Leinster House and their Oireachtas parliamentary party would jump from Division Three to Premier Division overnight.
For Sinn Féin, getting speaking rights in the Dáil would offer clear benefits. But what about for everyone else? The distinction that they wouldn't actually have seats is a false one. In reality, actually holding a seat and so a vote is not that important. The Dáil is rarely little more than a rubber-stamp.
It is having a presence in the Dáil, the profile it gives, and the ability to influence public debate that is crucial. All that would flow from speaking rights, irrespective of having actual seats.
Ireland has been famous for blurring the constitutional lines of normal demarcation on occasion. Between 1937 and 1949 Ireland, farcically, had both a king and a president while the Belfast Agreement was built on ambiguities which allowed Sinn Féin, though still possessing its own army, the Provisional IRA, to sit in the North's Executive Committee, while the DUP managed somehow to sit in, but not technically on, the Executive.
But the single most controversial blurring of lines occurred in the famed Articles 2 and 3 of the Constitution. The articles contained what were in theory mutually contradictory statements. Article 2 spoke of the "national territory" as including Northern Ireland. But Article 3 said that, notwithstanding this, the national parliament would not govern this "national territory", but only the 26-county bit of it formerly called the Irish Free State.
It could be argued that those articles might have given some sort of constitutional right, or at least constitutional ability, for Northern MPs, given that they were elected on part of the national territory, to at least speak in the Dáil even if not as full members.
Yet ironically, the Belfast Agreement which Sinn Féin itself championed, may have removed that constitutional option, with the new Articles 2 and 3 replacing assertions of an all-island "national territory" with a recognition of two separate states on the island, coupled with a non-claim based expression of a desire for unity.
Of course the Oireachtas does allow guest speakers to address it. But those addresses are once-off occasions, not the continuous right to participate that Sinn Féin is seeking.
Northern Ireland people are also eligible to sit in the Seanad as nominees of the Taoiseach. But nominees have an explicit constitutional status.
Giving a right to participate in the Irish parliament to people who hold offices not recognised in Bunreacht na hÉireann, who weren't elected in elections regulated by Irish law, and who were chosen to belong to an entirely different parliament by people not registered to vote in elections in the Republic, would be a constitutional revolution.
It would raise other practical issues: given that there are limited timespans available for individual Dáil debates, including Sinn Féin MPs would mean less time available for elected TDs to speak. If they wish to participate in debates they would need office facilities in Leinster House, and secretarial facilities, all of which would have to be paid for by taxpayers who would find themselves paying for politicians they did not elect and could not fire. Meanwhile, those same Northern politicians could find themselves advocating the spending of State resources that they themselves don't contribute to because they are not Irish taxpayers.
Giving speaking rights would also affect the Belfast Agreement. For one party, for its own benefit, and to further its own agenda, unilaterally to demand a right for some of its members to participate in a parliament they had not been elected to, would hardly embody the cross-party, cross-community consensus that is supposed to be at the heart of the agreement. Saying that other parties' MPs could if they wish do the same, when it knows on principle they would not want to, would be no excuse.
On balance, it is hard to see constitutionally how people who have not been elected to Dáil Éireann could be given a right to participate in it. If non-elected figures were given that status it would undermine the whole idea of the Dáil as a house entirely made up of politicians whom the people can hire and fire at will.
The ultimate paradox would be that Sinn Féin MPs in Leinster House would bear uncanny parallels to Lords in the British parliament. Like peers, they would be participating in a parliament they weren't elected to. Like peers, their membership would not start and end with the election and dissolution of that parliament. So, while everyone else would have to fight in each Irish general election to keep their right to speak in the Dáil, MPs like Gerry Adams and Martin McGuinness, with safe seats as MPs (and the British electoral system, unlike the Irish one, makes it all too easy to have safe seats), could have a right to participate in the Dáil almost in perpetuity. They could all too easily become a form of life member, sitting in someone else's parliament, with someone else paying their expenses, to try and shape public policies in someone else's state, all while, ironically, not sitting in the parliament they were elected to.
Jim Duffy is a historian and political commentator