Has Labour committed to supporting a second referendum?

Yes, in principle. But not quite yet.

The party wants MPs to vote on its own Brexit plan on Wednesday first, when the next round of motions about the UK’s withdrawal from the European Union are debated in the Commons.

That is expected to be defeated, at which point Labour has announced it is “committed to also putting forward or supporting an amendment in favour of a public vote to prevent a damaging Tory Brexit being forced on the country”.

No date has been set for the next round of votes, but Theresa May has said that she will put her Brexit deal to the vote on 12 March. A second referendum amendment is expected then.

What amendment will Labour’s frontbench support at that point?

This is not decided. One possibility is that Labour will back the so-called Kyle-Wilson compromise, an amendment being promoted by two Labour backbenchers, Peter Kyle and Phil Wilson.

The essence of their amendment is that Labour would allow May’s Brexit deal to pass the Commons in return for it being subject to approval via a second referendum.

Quick Guide Labour's key moments in the Brexit process Show August 2016 Making explicit the position he held since the Brexit vote, Jeremy Corbyn says Labour will respect the result of the referendum. "I think we've had a referendum, a decision has been made, you have to respect the decision people made." June 2017 Wary of upsetting voters in leave areas, Labour's manifesto for the 2017 general election declares: "Labour accepts the referendum result and a Labour government will put the national interest first." September 2018 Over five gruelling hours, Labour's internal contradictions over Brexit are distilled into a conference composite motion that makes the party's priority to seek a general election but, failing that, says a referendum should not be ruled out. February 2019 Chuka Umunna and remain MPs from both Labour and the Conservatives quit to form the Independent Group, citing Brexit as a major motivating factor. March 2019 Labour backs attempts by backbenchers to keep the option of a public vote on the table to stop a no-deal Brexit or May's deal. When all options considered by parliament fall, Labour enters into Brexit talks with the government but says May must move on a customs union if they are to succeed.

But there are deep reservations about the Kyle compromise in some Labour circles because it would involve Labour allowing May’s Brexit deal to pass. When asked about the amendment, a Labour source repeated that the party “would not vote for a damaging Tory Brexit”.

Kyle himself says that Labour could abstain to allow May’s deal through but that may not persuade the doubters. On the other hand, without promising that Labour would allow May’s Brexit deal through parliament, there is no realistic prospect of attracting Conservative support.

Is there a majority for a second referendum, even if Labour were to back it?

Probably not, although it is not certain. The Manchester Central MP, Lucy Powell, estimated that there would be 25 Labour MPs who would simply not support a second referendum, regardless of how a motion backing it would be phrased.

Only a handful of Tories support a second referendum – probably fewer than 10 – so without the support of Downing Street, it remains very unlikely to pass the Commons even with Scottish National party and Liberal Democrat support.

Is the point of Labour’s move to head off further defections to the Independent Group?

The strength of Labour’s move is that it helps bring the parliamentary party together, at a point when the Conservatives are increasingly divided over a no-deal Brexit and the anti-Brexit Independent Group is hoping for more defections from Labour.

The principal issue uniting the eight former Labour and three former Conservative MPs in TIG is opposition to Brexit and support for a second referendum. By finally opening the door to supporting a second referendum, Labour closes off their principal selling point.