Labour is to back a second referendum on any Brexit deal negotiated with Brussels, Jeremy Corbyn has told the shadow cabinet.

In comments that mark the first time the Labour leader has unequivocally endorsed a fresh vote, Corbyn said that the party's position was now "to demand that any deal is put to a public vote".

Until now, Corbyn has always caveated his support for a second referendum with the assertion that voters could be given a say via a general election - a form of words he stuck to in the immediate aftermath of the European elections, despite Labour's poor third place and dissent from loyal shadow cabinet ministers, most notably John McDonnell.

Yet it is not the unambiguous endorsement of Remain some in Westminster had expected. Corbyn told the shadow cabinet this afternoon:

"We have committed to respecting the result of the referendum, and have strongly made the case for an alternative plan for Brexit as the only serious deal that could potentially command the support of the House. "At Conference last year we passed our policy, the members' policy. Over the past nine months, I have stuck faithfully to it. "A no-deal Brexit would plunge us into the worst excesses of disaster capitalism and trash our economy on the back of fantasy Tory trade deals or worse, very real and very damaging trade deals with Donald Trump, opening up our NHS to American companies. "I have already made the case on the media and in Dublin, that it is now right to demand that any deal is put to a public vote. That is in line with our conference policy which agreed a public vote would be an option. "A ballot paper would need to contain real choices for both leave and remain voters. This will of course depend on Parliament. "I want to hear your views, I will be hearing trade union views next week, and then I want to set out our views to the public."

Notably, Corbyn's words fall some distance short of the shift to an explicitly pro-Remain position demanded by Tom Watson and Keir Starmer. It is also worth noting that Corbyn, who previously advocated a new public vote as a means to stop no-deal or a "damaging Tory Brexit", told Labour MPs last month that he supported the principle of a vote on any deal. As such, the policy position itself is not new.

So in so far as today's statement represents a shift, it is a modest and rhetorical one. The only real concession Corbyn has made to Remainers in the shadow cabinet and PLP is that he has stopped suggesting a general election could resolve the impasse. And as he stressed, any real movement - both on the precise question posed in a second referendum and Labour's campaigning - will be subject to bitter and protracted litigation within the shadow cabinet and among union leaders.

Though opponents of a new poll are on the back foot, they are not without ammunition: the shadow cabinet has also been warned that an explicitly anti-Brexit position might not be enough to win back sufficient numbers of Remainers to offset the risk of losing Leave voters in the key marginals in the North and Midlands the party must hold and win to have any chance of winning the next election.

As much as the tide has turned in favour of Labour's Remain tendency, it is unlikely to get the answer it wants this side of the Conservative leadership election - and there is no guarantee it will get the answer it wants at all.