One of the keys to petrochemical giant Shell’s sustained success has been its Scenarios department. According to its website, these scenarios explore “possible versions of the future by identifying drivers, uncertainties, enablers and constraints, and unearthing potential issues and their implications”. Party members and strategists alike will be familiar with this type of exercise, as we all try to play the electoral tape through to the end. Surprising, then, how little has been made of the long-term incoherence of the ‘Referendum and Remain’ position.

Supporters of this policy believe that the best deal available to the UK is EU membership. Calling on Labour to commit not just to a referendum on any Brexit deal – as is current policy – but also to campaigning for Remain in that referendum is thus an understandable next step. As has been hinted at on LabourList before, however, the unspoken logic of Referendum and Remain is that Labour would no longer seek to negotiate a different Brexit deal at all, since it would then be obliged to campaign against it – a point Wes Streeting, an advocate of the policy, has also acknowledged.

This is just the tip of the iceberg. The more you game out Referendum and Remain, the less useful this policy seems in the long term. It is not the function of the opposition merely to oppose – it needs to be a government in waiting. This means adopting the policies it intends to pursue in power. Working backwards from a Labour general election victory, it is unclear how a policy of Referendum and Remain meets this test. Given the very real prospect of a successful no-confidence vote in the next Prime Minister, electoral coherence is a legitimate consideration for the Labour leadership.

Were Labour to win a pre-Brexit early election on a Referendum and Remain platform, the logic of a second referendum is immediately diminished. Would it not be more logical for the new government simply to proceed to Article 50 revocation? Why would the party, having so recently gained a mandate from the people for its Remain stance, put itself on the hook to deliver Brexit (should the subsequent referendum go against them)? It would send the country back to square one – only then it would be up to Labour to implement a policy against which it had explicitly campaigned not once but twice. It appears that revocation, not a referendum, is the logical conclusion of the policy being proposed.

This is a problem because Referendum and Remain is premised and sold on the idea of any deal being put to the people, versus the option to Remain. While in opposition, this works fine. But in government, with responsibility for securing a deal – if only for it to be put to a referendum – the logic is much less clear: it seems doubtful that a Labour government would either commit to campaign against its own new deal, or seek to pass Theresa May’s withdrawal agreement – having so routinely disparaged it – purely for the purposes of having a leave option on a referendum ballot paper.

It is unclear whether Labour would ever go into an election committed to Referendum and Remain for these reasons. The only alternative would thus be for Labour to campaign for revocation of Article 50. My instinct, though, is that many second referendum supporters are less enthusiastic about the optics of pivoting to revocation, however logical a progression it may be.

Referendum and Remain only seems tenable so long as Labour are in opposition. Jeremy Corbyn and his allies have often been accused of being more interested in fighting the good fight in opposition than making tough decisions in government. But surely Labour cannot claim to be a credible government-in-waiting while advocating in opposition a policy that it does not intend to pursue in government.

I do not doubt that the leader’s office has already thought through these ramifications. Its reluctance to move to a Referendum and Remain position may well stem both from a (legitimate) desire to avoid the perception of abandoning Leave voters and from concern over the practical evolution of such a policy. While proponents of the shift are right that, given the October Brexit deadline, Labour needs to position itself for the present, it is also fair to highlight the longer-term complications of their preferred solution.