This week saw the first salvo in a legal challenge which, if it succeeds, will precipitate a constitutional crisis.
A letter before action sent by a London solicitor’s firm warned the government against making a confidence and supply agreement with the DUP’s 10 MPs, claiming that to do so would be a breach of the 1998 Belfast (Good Friday) Agreement.
An unintended consequence of the action being successful would be that Northern Ireland’s voters would no longer have equal representation in the House of Commons; by implication the nature of the Union would have been fundamentally altered.
The genesis of this challenge lies in the frenzied days immediately after the general election when the rest of the UK was coming to terms with the consequences of the result and questioning the nature of the DUP, the party which now holds the balance of power at Westminster.
One of the earliest concerns expressed about such an arrangement was that it could either lead to a return to violence in Northern Ireland or be contrary to the Agreement.
The aspect of the Agreement which is central to the challenge which is now being taken by solicitors Edwin Coe LLP on behalf of West Tyrone Green Party candidate Ciaran McClean is actually contained within the British-Irish Agreement, which was between the British and Irish governments.
It states that “whatever choice is freely exercised by a majority of the people of Northern Ireland, the power of the sovereign government with jurisdiction there shall be exercised with rigorous impartiality on behalf of all the people in the diversity of their identities and traditions and shall be founded on the principles of full respect for, and equality of, civil, political, social and cultural rights, of freedom from discrimination for all citizens, and of parity of esteem and of just and equal treatment for the identity, ethos and aspirations of both communities”.
That commitment to “rigorous impartiality”, contends the legal challenge, is incompatible with one unionist party propping up a government which then has to act equitably on matters about which the DUP – on which the government depends for its survival – cares passionately.
It has to be said that such an argument was never advanced at the time of the 1998 referendum on the Agreement. Had it been, it would have had a significant impact on the campaign.
And a more obvious reading of the words in question would suggest that the thrust of their meaning is that the government must not discriminate against any community in Northern Ireland – an obvious concern, given Irish history – rather than some blanket prohibition on Northern Ireland’s MPs supporting a government.
It is also clear what those words do not mean. They do not mean that the British (or the Irish) government should be neutral on Northern Ireland’s constitutional position – neither government is neutral in that regard.
It is also not a suggestion that the government cannot agree with one or other parties in Northern Ireland – overlapping policies have seen Labour and Tory governments agree with all sorts of parties (and struck deals to secure Commons’ support as necessary) since 1998.
And it does not mean that the government must be “rigorously impartial” in all of its dealings with Northern Ireland – the government, for instance, takes the firm view that IRA bombs were and remain unjustified, a view not shared by Sinn Fein and which is relevant to the current Stormont talks which the government is chairing.
The legal challenge which started this week with the sending of a solicitor’s letter to the government is not a challenge to the specific nature of what the DUP and the Tories have agreed – that much is clear because we do not know what will be in the deal.
Rather, it is a challenge to the principle that a Northern Irish party could strike a confidence and supply agreement with a minority government.
Such an agreement is the bare minimum which is necessary to indicate support for a prime minister and falls far short of entering a coalition to actually govern, although logically that would also be against the Agreement if this case succeeds.
As it happens, the DUP is now the only Northern Irish party to sit in the Commons but the grounds on which this challenge is being taken suggest that this challenge would apply to any other party representing Northern Ireland’s electors. The implications of that argument are profound.
It is of course the case that as a region which makes up 2.8% of the UK population Northern Ireland’s MPs are unlikely to often be in a position of critical influence – either in key Commons’ votes or in deciding who governs.
But until now a key constitutional principle has been that each constituency in the UK returns an MP with the same rights, responsibilities and pay as those from every other seat across England, Scotland, Wales and Northern Ireland (the West Lothian question aside).
If this case succeeds, Northern Ireland’s people would be permanently – and uniquely – excluded from ever playing a direct role in choosing the government which taxes them, which sends the Royal Irish Regiment to war, which sets their pensions, which decides on immigration policy and myriad other areas which directly impact on their lives.
But, even if this case succeeds, it is difficult to see how it could ever be enforced.
If the DUP is barred from striking a formal confidence and supply agreement with the Tories, the party would still be free to publicly state that it will support the government.
And although such a scenario would perhaps not involve a published list of the financial blandishments which the party is now seeking for Northern Ireland, a prime minister heading a minority administration would still know that she served at the pleasure of the party holding the balance of power.
Therefore, due to the ineluctable arithmetic of this Commons chamber, the DUP would retain its king-making position and thereby exert influence on the government.
Even the courts could not prevent that.