Another day, another Labour policy on Brexit. Readers could be forgiven for thinking that the latest edition of the endlessly mutable Opposition view on leaving the EU is something to note, at most, and then disregard on the basis that it will surely be abandoned and replaced in time, like all its predecessors.

That may well prove true, but there are good reasons to pay attention to the newest change.

First, its timing. There is less than a week to go until the battle royale in the Commons over the various amendments proposed to the Withdrawal Bill – and the fate of the most controversial and finely-balanced votes will likely come down to how Labour MPs (pro-EU, anti-EU, and obedient factions) vote or abstain. Various of the pro-EU hardliners on the backbenches have been pressing for Labour to support the EEA amendment, believing it a viable way to wreck the Brexit process which might attract the support of sufficient Tory rebels.

It is therefore very significant that, rather than accede to that demand, the Labour leadership has proposed a new alternative amendment. Stephen Kinnock and other Remain ultras are furious at this new policy, on the twin grounds that it is in effect a rejection of the EEA option, and that they believe the Tory rebels (with whom they surely have some contact) will be less willing to support a formal Opposition proposal than a Lords or backbench initiative. Privately they suspect that this is Team Corbyn repeating their performance in the referendum campaign, in which they served mainly to make life harder for Remainers – Ben Bradshaw cites it as evidence that his Party is not “serious” in its opposition.

Second, the strategy. If Corbyn just wanted to clearly reject the EEA option, he could do so. But remember the strategy of deliberate ambiguity, on Brexit and other issues. He does not seem to want to do what pro-EU obsessives desire, to the extent that he is willing to pay the price of disappointing them if necessary, but if there is a way to excuse and dissemble his way through and thus minimise the anger then he will do so. This new position is presented not as a way to wreck the EEA push, but as a further step towards limiting Brexit – something for which Remainers are told they ought to feel grateful. It’s classic Corbyn – throw enough chaff about to confuse the issue, then ride on the accumulated willingness of his supporters to think the best of him in all circumstances. In this instance, his use of ambiguity is further eased by the fact that the Government’s own position is not exactly one of hard-edged clarity.

Third, the detail. As is probably clear from the above, this isn’t just the latest Labour Brexit policy, it’s the latest impossible Labour Brexit policy. It rests, at its heart, on a version of the promise to deliver the “exact same benefits” of the Single Market which Barry Gardiner previously described as “bollocks” – adding that it “always has been bollocks and it remains it.” Speaking in March, Gardiner was recorded saying that “we know very well that we cannot have the exact same benefits”. If they knew it then, they still know it now.

Fourth, and more ominously, it implies they will pick a fight elsewhere. There are 15 amendments to choose from, and the Government has not yet made up its mind on how to deal with all of them. Some are viewed as simply unacceptable and will be opposed in all circumstances, while some are felt to be essentially irrelevant. Tory would-be rebels expect some kind of concession, though nobody yet knows what on. If Labour isn’t going to back the EEA amendment, that doesn’t mean it won’t seek to defeat the Government somewhere – indeed, it’s surely a sign that they are keeping their powder dry for a vote on which they believe they can win and cause damage. It could be the meaningful vote, it could be the date of Brexit, it could be the Customs Union. It could be all three.