Parliamentary arithmetic may provide a bulwark against a “no deal”…

So if the hard realities being expressed in Dublin are changing around Brexit, so too in Westminster, where the arithmetic remains eye-wateringly tight.

An old friend once told me that with any 50/50 decision as things inevitably get harder, the slim positive majority melts and the will to carry it forward gets much tougher maintain. Very quickly.

The last general election delivered just such a scenario. No one has a mandate to undo Brexit, but no one has the electoral dominance to make a long term social and/or economic success of it either.

This may explain the emergence of no deal fantasies, the British counterpart to the EU’s insistence that rejection of the backstop – that few Remainer Unionists want – would lead to a no deal.

So the EU side has quietly dropped it, demonstrating that most of what we’re witnessing in the run up to the deal itself is a gaming of public opinion more than anything of particular substance.

Today the Irish Times has reprinted an OpEd from Jonathan Lis, deputy director of the think-tank British Influence which has a solid track record on providing non hysterical analysis on Brexit.

In it, he lays out the domestic political reasons why a no deal scenario is highly unlikely (although, of course, not impossible):

First, the political reasons. Chief among them, Theresa May . She will not accept a no-deal scenario. Everything she has done so far demonstrates her terror of it.

The EU has called her bluff on the negotiation sequencing, divorce payment, Irish backstop and transition terms, and to keep the show on the road she has blinked each time.

Assume then that May folds and subsequently resigns. The new prime minister declares that no deal really is better than a bad deal.

He or she needn’t come clean about the consequences: reality will step into the breach. Put simply, Britain will start shutting up shop by the new year.

Tens of thousands of EU citizens will leave, manufacturers will make show-stopping announcements about the closure of businesses, and the pound will tumble.

Can the new prime minister depend on voters’ enthusiastic embrace of an entirely voluntary and pointless Blitz spirit, or will they call for a climbdown?

Imagine the political crisis escalates. The prime minister faces down public pressure to change course and has to confront parliament. Which brings us to the other key block for no-deal: parliamentary arithmetic.

Tory MPs have so far largely swallowed a hard Brexit they do not want. But a no-deal is an unprecedented catastrophe. Many shy rebels will draw the line at licensing national suicide on principle.

Others will think more politically. A Tory government that sends the economy and livelihoods over the cliff will collapse the Tory party for a generation. Even MPs who would not save the country might opt to save themselves.

Labour , for its part, declared a no-deal scenario its red line in the 2017 election manifesto. Even a handful of extra Tory rebels would break the government’s Brexit majority.

After all, government whips last month threatened MPs that losing a key Brexit vote would trigger a general election, and still only won by six votes. [Emphasis added]

Parliament is and always has been a bulwark against what Burke called the enthusiasms of young men (though in the case Brexit, some have kept their youthful folly intact for a very long time).

Mick is founding editor of Slugger. He has written papers on the impacts of the Internet on politics and the wider media and is a regular guest and speaking events across Ireland, the UK and Europe. Twitter: @MickFealty