Corbyn hasn’t bottled it. He’s served an ace.

Jeremy Corbyn’s stated position on a new customs union is a genius political move.

Since the negotiations started, the EU has made great capital out of the Irish border question, using it to trip up negotiations and present itself as the only entity soberly considering the issue, often sending its supplicant Leo Varadkar out to do its dirty work on the dirty networks.

Corbyn’s proposal for a new customs union solves the Irish border question, and a whole lot more.

The only difference between Corbyn’s proposed custom union and the EU’s existing one is that the EU would need to be a partner, and not a setter of rules. The UK would have a say in setting import tariffs.

The UK’s right wing press can bray as much as they like about “bottling” or “betrayal”, but Corbyn was quite specific about that. The UK will not be a rule-taker, not without input.

Besides, it’s not even clear, or likely, that the EU will accept the proposal. History has shown the Union to be inflexible when faced with challenges to the project.

An agreement under these very reasonable terms is reasonably unlikely, because it will achieve the exact opposite of what the EU is looking to achieve in these negotiations.

It cannot afford an exit being a success story. Other nations would look to get out too.

To give the UK parity with 27 other nations in non-EU tariff arrangements would be an instant success story.

On previous form, the European Union will put the project above other practical considerations, including the Irish border question.

The British don’t want a border, and the Irish don’t want a border. The only people that have been hyping up the border as an inevitability have been pro-Europeans and the EU itself.

Bertie Aherne, former Taoiseach, believes that ultimately, common sense will prevail, even if that involves authorities turning a blind eye.

So why is Corbyn’s proposal so politically adroit?

It’s near-identical to the EU’s existing Customs Union, so it cannot be branded as fantasy, as Tory plans have been, or “impossible”, because it already exists.

It is not a transitional arrangement. It is permanent, providing much of the certainty that businesses across the continent have been asking for.

This is an offer the EU both can’t refuse and must refuse.

If it accepts, it imperils the project, because it’ll give succour to Eurosceptics across the continent. It’ll be petitioned from within by countries looking for concessions of their own.

If it refuses, it imperils the project, because it will have rejected solutions to some of the most pressing problems of Brexit, because of one little difference. Not having total control.

The Conservatives have had the political shit kicked out of them by the European Union in these negotiations.

In this one move, Corbyn has thwacked the ball into the EU’s court, got the umpires asking how much the EU really cares about the Irish border question, and set the stage for a government defeat.

That is why it is genius.