The declaration by Sir Mark Sedwill, Whitehall's most senior civil servant, that Northern Ireland faces direct rule from London if the UK quits the European Union without a deal has not surprised.
In the past month Northern Secretary Karen Bradley and environment secretary Michael Gove have spelt out in the clearest of terms that such an outcome is the almost inevitable upshot of a no-deal Brexit.
Nevertheless, the leaking of extracts of Sedwill's letter to Tuesday's Daily Mail has heightened fears that such an exit could further undermine the Belfast Agreement and sound the death knell for Stormont, mothballed and all though it is.
Sedwill states the matter bluntly, “The current powers granted to the Northern Irish Secretary would not be adequate for the pace, breadth or controversy of the decisions needed to be taken through a no-deal exit. Therefore we would have to introduce direct rule.”
Downing Street, according to good sources, has already informed the Government. Dublin would be upset, but it is unlikely to be surprised.
Because of the collapse of devolution 27 months ago, Northern Ireland now effectively is run by civil servants. But under current legislation they are hamstrung by an inability to take key decisions in many areas.
However, Stormont’s paralysis would be magnified by a no-deal Brexit. Emergency actions to cope with shortages of medicines or fuel or traffic jams at ports could overwhelm senior civil servants left with limited powers to act.
Extra burdens
And even were some form of direct rule to return, with British ministers rather than Stormont Assembly politicians taking key decisions, there is a worry about even Westminster's ability to cope with extra burdens.
Shuddering at the thought, one well-placed source said: “The British government can’t manage their way out of a paper bag at the moment, and neither can the House of Commons, so to take on direct rule in a situation where there is increased division and polarisation in Northern Ireland even before Brexit, and then to put all of the Brexit weight on top of it, well how would that work?”
In slightly more measured tones, he added: “Direct rule in the Northern Ireland context at the moment would require great levels of skill and attention, which seems to be absent from the British system at this time.”
While a return to direct rule would infuriate Sinn Féin and the SDLP, it should be a situation that the DUP, even if is a devolutionist party, could live with.
Reflecting Sinn Féin's viewpoint, Newry and Armagh Sinn Féin MP Mickey Brady said direct rule "would be totally unacceptable, and yet another breach of a political agreement".
“The letter from Mark Sedwill is further evidence of the dysfunction and reckless disregard at Westminster for the interests of the people of the North.
“In the event of a no-deal crash-out then the only logical thing to do is allow citizens to democratically decide on our constitutional future through a Border poll as provided for by the Good Friday agreement.”
Power-grab
SDLP leader Colum Eastwood MLA accused the British government of continuing "to talk up the prospect of direct rule but they have yet to call the parties together to talk out the challenges to restoring devolution".
“A Westminster power-grab solves nothing, and is being facilitated by the failure of the DUP and Sinn Féin to get back to work.
“All parties need to come together, talk through the challenges, and take back control of our health service, schools and all the other public services that have been left to drift.”
However, the DUP would not be pleased by the declarations from Ms Bradley and Mr Gove that Dublin would have an input into direct rule as allowed under the international treaties of the Belfast and St Andrews agreements.
In such a situation the Irish Government would push for regular meetings of the British-Irish Intergovernmental Conference to try to mollify nationalist fury.
“For the DUP the threat isn’t direct rule, the threat is Dublin’s involvement,” said a senior source.
But it all would be very unhappy and fraught, and yet another sign that the hope of Good Friday 1998 and of the DUP agreeing to share devolved power with Sinn Féin in 2007 are being blown apart by Brexit.