OK, so you tell me why Corbyn wants the UK to leave the EU.
All the "Corbyn is actually a Leaver!" stuff always ignores the fact that he put Starmer in charge, rather than someone more Lexity, like Gardiner. But never mind that. Let's say Corbo and McDonnell are actually, in their hearts, committed Leavers. What kind are they? Are they pragmatic Leavers, who'd like to get out of the EU because they think the EU will block their reform program? Or are they ideological Leavers, the left equivalent of the ERG sovereigntists, who hate the EU for what it represents and want to leave at any cost - that is, are they prepared to burn down the country for an idea?
It's not the latter is it? And if it's the former then they'd surely already have considered something that only just seems to be dawning on the ERG: that leaving an enormously powerful trading bloc doesn't free you from it. May's deal makes this clear: it will be
harder for Labour to put their reforms into actions outside the EU than within it - the EU will have
more leverage to block reform.
ISTM that either Corbyn and McDonnell get this, and don't actually want to leave, and are working for the softest possible Brexit and maybe Remain, or...they really are the ideological nut jobs some people think they are, and are willing to inflict suffering on the people they've dedicated their lives to helping for the sake of their pathological hatred of the EU. Which would actually make them nuttier than the ERG.
I don't know. Maybe they have some secret plan for a managed hard Brexit that squares all the circles and builds in defences against attack from the EU. But I think the likeliest scenario is that Starmer's plan is actually the plan and that Labour are going for softest possible Brexit or possibly Remain.