Labour is discussing the prospect of a new Brexit referendum with the government, Jeremy Corbyn has told his MPs this evening.

In an email to the parliamentary Labour party, the leader of the opposition said the “detailed technical discussions” between Keir Starmer, the shadow Brexit secretary, Rebecca Long-Bailey, the shadow business secretary, their Tory counterparts Steve Barclay, and Greg Clark, as well as David Lidington, the Cabinet Office minister, had covered a “confirmatory vote”, as well as single market alignment, workers’ rights, and customs arrangements.

Corbyn’s confirmation that the negotiations include serious discussion of a second referendum comes despite Theresa May rebuffing the idea in their meeting yesterday. The Labour leader told the PLP last night that the prime minister "remained resistant" when he raised the idea of a new vote, which many MPs and several members of the shadow cabinet, including Tom Watson and Emily Thornberry, say must be included in any deal the two parties reach.

Strikingly, there is no such caveat in this evening’s message – though it should of course be read in context. Starmer and Lidington, May’s de facto deputy, are both much more sympathetic to the case for a confirmatory referendum than their respective leaders and it is not the case that discussions between these sets of negotiators would necessarily end with agreement between May and Corbyn (or, indeed, between Starmer and shadow cabinet ministers who are cooler on the idea of a new poll, like Long-Bailey).

Nor is it the case, more importantly, that today's discussions will necessarily result in any concrete concessions from the government. None have yet been forthcoming.

Corbyn’s email – the full text of which, passed to the New Statesman, is below – also confirms that Labour wants any commitments made by May enshrined in law, which could prove an impossible ask for a Prime Minister who only came close to winning round all of her MPs once she had promised to stand down ahead of the next phase of Brexit talks on the future relationship. But as far as the Labour leadership is concerned, legal guarantees are essential. As one source said after the prime minister made her offer: “How can May 'agree an approach' to phase two when she has committed to standing down after phase one?”