So far, Jeremy Corbyn’s Brexit strategy has just about worked. Not that he has facilitated any progress, or sunk anything he dislikes, particularly – but then that isn’t his objective.

Rather, he has worked extremely hard to fulfil two goals. First, leave the Government to its struggles. Second, at best satisfy, and at worst not excessively alienate, two directly conflicting groups within Labour’s electoral coalition: Leavers and Remainers.

As time has gone by, the pursuit of that second goal has naturally become more defensive, increasingly focused on providing what cover and excuses it can provide to defend against criticism. It’s instructive to consider any Corbyn Brexit comment through that lens – he reliably seeks to avoid being accused of blocking Brexit, but also to avoid being accused of facilitating it. That essentially inactive approach helps to fulfil the initial goal of not doing anything to alleviate the Government’s woes.

It’s clever, if cynical, and it has served the Opposition Leader pretty well for two and a bit years. However, it is becoming more difficult to sustain as Brexit Day approaches.

For a start, each passing day reduces his ability to brush off the B-word and focus the discussion on austerity or inequality or something else more resonant with his target voters. Labour managed to shift the 2017 General Election onto such topics, but it is less plausible to try to avoid Brexit discussions with only 50 days until we leave the EU.

Even more pressingly, that approaching deadline is causing intense angst, particularly among the Remainer wing of his Party. Some allowed themselves to believe his hints that he disliked Brexit, and disregarded the evidence to the contrary, and are now horrified that he might allow it to happen. Others prioritise avoiding either Brexit itself or a No Deal outcome above things like winning power, but are now starting to realise that governing trumps such concerns in Corbyn’s list of priorities. The pressure on the leader to do something – anything, rather than his existing stance of artful nothingness – on Brexit is mounting.

Today’s letter from Corbyn to the Prime Minister is born of that context. If he could get away with doing nothing, he would, but evidently he feels his two competing groups might be drifting apart. So he has made some concessions, in an effort to keep them just close enough together to get by a little longer.

That explains why the shift in Labour’s position seems at odds with itself: it is, because it is intended to communicate different things to people who disagree with one another.

Accusations that he was unwilling to even talk with May, or do anything to help fulfil Brexit, appear to have stung – so this letter is portrayed as reaching out to find a compromise. So, too, did the claims that he was raising the risk of No Deal through his intransigence, so he is trying to display his willingness to avoid that outcome. At the same time, he has no wish to seem to aid a “Tory Brexit”, so he includes demands – such as eternal EU power to make swathes of new laws restricting the labour market – that he knows the Government cannot agree to. Finally, he knows how unpopular a second referendum would be, and signally has refused to lend any support to the idea that it is an alternative to his proposal (while falling short of ruling it out, in the hope that he won’t upset its fanatical supporters too much).

The ideal outcome for Corbyn is to minimise blame while maximising chaos, both of which would serve his overriding goal of winning power. The tightrope he must walk to do so is getting thinner, and the wind is getting up, but thus far he has maintained his balance. He evidently believes that the Government will teeter before he does – and that the disgruntled Europhiles on his own backbenches will lack the gumption to act in time to stop him. From past experience, you can see why he might think so.