Since nearly all of his career has been spent in rebellion against his own party, I guess we should not be too surprised that Jeremy Corbyn seems so determined to defy it over Brexit. Labour members hate Brexit and they want it reversed. With parliament deadlocked and growing public support for taking the question back to the people, a large majority of Labour voters, and an even larger majority of Labour members, wants the party to throw its weight behind another referendum. Compare and contrast with a Labour leader who doesn’t hate Brexit, doesn’t want it to be reversed and will not help facilitate another referendum if he can possibly avoid it.

That divide between leader and members has been pretty obvious for a long time to anyone who contemplated Mr Corbyn with clear eyes rather than wearing soft-focus lenses. The split has become more evident as the Labour frontbench has run through various tactical ruses to try to mask the tension between its members and its leader. He is what he is and that is a lifetime opponent of the EU. He has not once expressed a flicker of remorse about the result of the 2016 referendum and treats the momentum behind a second referendum not as an opportunity to be seized, but as a threat to be smothered.

It is true that Labour’s position has been deliberately fogged in ambiguities, but where Mr Corbyn really stands has always been deducible so long as you were prepared to listen properly. Back in November, he was asked: “If you could stop Brexit, would you?” He replied: “We can’t stop it. The referendum took place. Article 50 has been triggered.”

He said that even though his party conference had only recently adopted a policy that was supposed to keep another referendum on the table. He really couldn’t have been clearer in November that he doesn’t believe in that policy, but some people weren’t listening then or they pretended not to hear him because it conflicted so starkly with the naive image of the Labour leader that they had constructed for themselves. This left them open to being shocked when he said, just before Christmas, that he would not seek an escape from Brexit even if there was an election in the near future and Labour won it.

The promise to obey the members was easy to keep so long as their desires converged with those of the leader

I suppose you could argue that Mr Corbyn is being consistent with his convictions – or at least one set of them. But his increasing exposure as a Brexit-enabler does rather alter his profile as a rebel. During his decades as a dissident backbencher, he defied Labour leaders in the name of upholding true socialist values, as he interpreted them, against the treacheries, by his definition, of the party’s establishment. This record helped him win the leadership in 2015 with a promise to create a party in which the will of the members would be paramount. That promise was highly popular with Labour supporters. Who doesn’t like to be told that they will be listened to? It sustained him when he was under attack from Labour MPs. They, in turn, were threatened with deselection if they failed to defer to activists and comply with party policy.

The promise to obey the members was easy to keep so long as their desires converged with those of the leader. Labour activists like the idea of hiking taxes on the rich and taking the railways back into public ownership. So does he. Snap. Everyone is happy. The real test of his pledge to the membership was always going to be the hard cases where his ideological convictions came into conflict with what Labour people wanted. What would Mr Corbyn do when he and his members desired something contradictory? How would he act when they had fundamentally different worldviews? Would he put aside his own preferences in deference to the sovereignty of the Labour people? Or would he behave just like the “establishment” politicians he has spent a lifetime condemning and seek to subordinate the will of the members to his own opinions?

We now know. The Brexit blowtorch has burnt away many fantasises. One of the items on the bonfire of illusions is the notion that the Labour leader is in some way a special one, so different to all other politicians as to be almost not a politician at all. It turns out that he is just another manoeuvring, equivocating hack when he wants one thing and his members want the opposite.

This split is not a slight difference of opinion on a low-order issue. We are talking about something a bit more important than how to regulate the provision of manhole covers. This is about the most significant question to face Britain for decades. Some 73% of people currently identifying as Labour supporters think that the UK was wrong to vote to leave the EU. That rises to a whopping 89% among Labour members. As you might expect to follow, most Labour members and most Labour voters want the party to come out in full support of another referendum on Brexit, a move that would transform the chances of the country being given a fresh choice. In another referendum, 88% of Labour members and 71% of Labour voters would cast a ballot to remain within the EU. We know this thanks to the valuable work conducted by the ESRC-funded Party Members Project led by Professor Tim Bale of Queen Mary University of London. These are not finely balanced results within the margin of error. Labour members, supposedly the sovereign decision-makers within the party these days, want to remain within the EU by a thumping margin of nearly nine to one.

The Labour leader’s defiance of his members means he has something in common with Theresa May. She is also at odds with her grassroots. A hefty majority of Tory members don’t like the agreement negotiated by their own leader and the first preference of most of them is to leave at the end of March without any deal at all. That would be grotesquely irresponsible, so Mrs May can at least argue that she is trying to put country before party when she refuses to obey the demand of Tory members for a crash-out Brexit.

Labour members have displayed a great deal of loyalty to Mr Corbyn since he became their leader. But even a membership that has been willing to grant him the benefit of the doubt about so much else has begun to notice that he is defying them on Brexit. What’s interesting is how they explain this betrayal to themselves. Asked to say why he is failing to support another referendum, about a tenth think he’s just waiting for the right moment. Since there are now fewer than 90 days left before Britain is scheduled to be out of the EU, I admire these people for their patience more than I respect them for their judgment of character.

About a third of Labour members reckon he’s mainly worried about losing the support of Leave voters. This is certainly true of some members of the shadow cabinet who say things such as “we’ll lose the north”. But I don’t think it is the most important reason for being against a referendum in the case of the leader himself. Nearly a quarter of his members put Mr Corbyn’s unwillingness to embrace a people’s vote down to the fact that he actually supports Brexit. They have been paying attention. The clearest thing he said in his recent interview with the Guardian’s Heather Stewart was when he attacked the EU’s rules on competition and subsidies: “I don’t want to be told by somebody else that we can’t use state aid in order to be able to develop industry in this country.”

This will have a familiar ring to some older readers: it is a variation on one of the ancient arguments from the 1970s against Europe. It was often heard from Mr Corbyn’s antecedents on the left who opposed what was then the EEC because they saw it as nothing better than a capitalist club constructed to do down the workers and thwart socialism. It is highly disputable whether EU membership would prevent a Corbyn government from pursuing a state-directed industrial strategy. What matters in understanding him and his motivation is that he clearly believes this to be true. It is an argument he often returns to whenever asked about Brexit.

Sometimes, the simplest explanations for human behaviour are the best ones. The Labour leader is not making any effort to prevent Brexit because he doesn’t want to prevent Brexit.

The conclusion for Labour supporters ought to be clear. If they want another referendum, they will have to learn from their leader and rebel against him.

• Andrew Rawnsley is an Observer columnist