‘Don’t be surprised if Labour’s new “aim” is a moon-on-a-stick Brexit of one sort or another,’ I wrote on Friday in anticipation of today’s speech by Jeremy Corbyn. The latest position adopted in Labour’s great game of Brexit Twister obligingly fulfilled that prediction.

The expectation that Corbyn would move towards the possibility of a (or indeed the) customs union with the EU was very heavily pre-briefed by a whole range of his colleagues. Indeed, they laid it on so thick as to give the impression at times that they weren’t entirely confident that Jeremy would actually go through with it, and so needed to lock him in to his own announcement by telling everyone to expect it in advance.

Those who had hoped that the Labour leader could be relied upon not to flirt with such a position under any circumstances may well be disappointed. But then they probably ought to have studied the bitter experience of the pro-EU campaign during the referendum, who found out the hard way that he is not as steady as he likes to claim.

As it was, today’s speech saw the man-who-always-stands-by-his-principles attempt to adopt a policy generally at odds with those principles, while trying to maintain that he still stands by his old views as well.

A customs union was, apparently, something Labour had “long argued” was a “viable option”. But the Opposition wants one that allows Britain the freedom to make its own trade deals, to have “a say” in future EU trade deals, and that does not involve Britain becoming “a passive recipient of rules decided elsewhere by others”. Somewhat unfortunately, the reality of customs union is at odds with all three of those supposed red lines. Jeremy Corbyn’s pledge was being brutally undermined by Jeremy Corbyn’s own red lines.

It also seems that Team #JC4PM have been reading ConservativeHome over the weekend.

This site warned on Friday that a customs union would allow the EU to open up UK markets including the NHS through trade deals like TTIP without the UK’s permission. In an attempt to head off that threat, the Labour leader simply sought to rule it out: “Labour is implacably opposed to our NHS or other public services being part of any trade deal with Trump’s America or a revived TTIP-style deal with the EU”.

Again, though, he found his pledge at odds with the rest of his own speech. It’s hard to see how he could issue such a guarantee and support customs union with the EU, unless he is proposing that the EU would agree to grant the UK a veto on all EU trade deals – something Juncker et al are never going to give in a month of Sundays.

As expected, then, this was a speech from the same school of thought as John McDonnell’s pledges that nationalisation won’t cost anything; an argument resting on the assumption that true believers won’t look too closely at the fact that it is inherently contradictory.

Corbyn, as a long-standing critic of the EU, surely knows this. At times he sounded like he was reading out a carefully phrased armistice deal signed between different wings of his own Party – probably because that was exactly what he was doing.

Indeed, so have-your-cake-and-eat-it was his script that at one point his own subconscious seized control of his vocal functions and he blurted out “Join us in supporting the option of a new cake…” before correcting himself to “a new UK customs union with the EU”.

Genuinely, I’m not making that up, he said “cake” out loud in the middle of his speech:

As expected, though, he was offering not cake but yet more fudge.