The Staggers 15 November 2018 Dominic Raab’s resignation takes Britain to the brink of a no-deal exit Theresa May’s premiership is hanging by a thread, but more importantly, so is the United Kingdom. Getty Sign UpGet the New Statesman\'s Morning Call email. Sign-up Dominic Raab has quit as Brexit Secretary, and dealt a fatal blow to any hope that Theresa May's Brexit deal will pass the House of Commons and very probably to May's premiership as well. Raab's resignation changes the calculation as far as other cabinet ministers are concerned. It confirms what we already knew, which is that there are far too many Conservative MPs who are committed to voting against this deal for it to pass even with a substantial Labour rebellion. If you are Penny Mordaunt, playing a blinder as far as the leadership race is concerned at Dfid, why stay? If you are Esther McVey, why pass up the one opportunity for the word "resigns" to appear next to your name without the words "in disgrace" next to them? And doubtless many junior ministers will decide that their own futures are better served by quitting. It makes it much harder to see how May can remain as Prime Minister, but ultimately, the fate of May is almost entirely besides the point as far as the shape of Brexit and the fate of the United Kingdom are concerned. Here's what actually matters: our only land border with the European Union was the site of a civil war within living memory, and its constitutional status is still fiercely contested. The Irish government, with whom we share that border, has a veto over any negotiated end state. Just as no British prime minister could survive signing a deal that separated Northern Ireland from the United Kingdom, no Irish Taoiseach could survive signing a deal that put a hard border on the island of Ireland. In terms of Raab's resignation demands, they can only be met through a no-deal Brexit with all the attendant disruption. That sharply limits the potential deals that any Conservative leader can strike. A Tory prime minister can't negotiate a deal that takes the United Kingdom away from the customs and regulatory orbit of the European Union because that would either mean a border in the Irish Sea (unacceptable to the DUP, without whom they cannot survive in office, and to Conservative MPs, without whom they cannot remain as party leader) or a deal in which a border appears between Ireland and Northern Ireland, which the Irish government would veto. So all that is left is some flavour of negotiated Brexit that keeps the whole of the United Kingdom within the regulatory and customs orbit of the European Union or leaving without a deal. Whether or not May remains as Prime Minister, regardless of who is in or out of her Cabinet, that essential truth will not change. › Theresa May’s deal can’t pass parliament, says man who lost her majority Stephen Bush is political editor of the New Statesman. His daily briefing, Morning Call, provides a quick and essential guide to domestic and global politics. He also co-hosts the New Statesman podcast. Subscribe For more great writing from our award-winning journalists subscribe for just £1 per month!