We’ve covered before on LeftWatch the range of often conflicting positions on Brexit held by the Labour Party. At the moment, the one they choose to talk about most is the position stated in their manifesto – namely that they would reject a ‘no deal’ Brexit.

In terms of negotiation strategy, the naivety of such a position is extraordinary. Telling Brussels that under no circumstances would they leave without a deal is the same as offering to buy a deal of any quality at any price – an open invitation to the EU to make the worst possible offer, and demand the highest imaginable sum for the privilege.

The more they promote the idea – in the press, in the Commons and on the airwaves – the more they harm the prospects of a good deal. So travelling to Brussels to reiterate that message face to face with the EU’s negotiators, as Jeremy Corbyn did this week, is a remarkably unwise thing to do. Who did he think he was helping by doing so?

The most likely answer, so far as I can see, is that he though he was helping himself and himself alone. It’s not implausible that Corbyn doesn’t give a damn what impact his pronouncements might have on the national interest. After all, he holds plenty of other views that are harmful economically, socially and even physically to the UK, apparently without any qualms at all.

What appears to lie behind this particular calculation is the belief that appealing to those voters who hope to stop Brexit altogether is the route to electoral victory. While much of the evidence suggests that the result of the last election rested on the Conservatives drastically underperforming, and Labour’s position on austerity serving to reunite the left behind Corbyn, there’s a growing school of thought in Labour circles that attributes the outcome to winning over those voters who feel strongly about remaining in the EU.

Of course, a voter who hates Brexit choosing to vote for a Labour Party whose manifesto commits to leaving the Single Market might perhaps need to read a bit more closely, but it’s certainly the case that some only heard the hints that Corbyn was on their side, and voted accordingly. The more pro-EU members of the Shadow Cabinet therefore argue that hyping up outright disruption of the Brexit process will win yet more votes next time round.

What this analysis misses is that such a strategy can also come with a cost.

I recently heard Daniel Finkelstein present a compelling argument that the story of the 2017 election is as a failed – or at best half-complete – Tory realignment; that Timothy et al calculated it would be worth losing some of their better-off, more pro-EU voters, in exchange for winning over a large tranche of working class Brexiteers who had previously voted Labour, or Labour-and-then-UKIP.

Finkelstein suggested the campaign fell short because it successfully performed the first part of the operation but failed to fully secure the pay-off in winning over switchers, and it seems to me that he is right. Through their ambiguous position on Brexit, by emphasising austerity, and helped by Tory bungles. Labour managed to retain more Leave voters – and win back more former UKIPers – than the Conservative model intended.

Consider this week through that filter, then, while remembering that Leave voters as well as Remainers watch TV and read the newspapers. Corbyn travelled to Brussels, apparently to disrupt the Prime Minister’s efforts in the Brexit negotiations. His message is that he would give Brussels as much power and money as it might want, regardless of the wisdom of doing so.

That might play well with some of his intended audience – those who are still completely opposed to leaving the EU – whom he believes he needs to win the next election. But it will simultaneously play badly with another chunk of his vote – those who backed him for economic reasons, while assuming him to support leaving. At this rate, he might help the Conservatives to complete the realignment they failed to secure themselves.