Jeremy Corbyn's announcement that the Labour party is prepared to back another EU referendum to prevent a 'damaging Tory Brexit' was intended to placate Remain-leaning MPs. However, it's also managed to irk those Labour politicians representing Leave seats. Tonight MPs gathered for a fiery meeting of the Parliamentary Labour Party. It was standing room only as MPs crowded in to try and make sense of the latest Brexit development.

Addressing MPs, Jeremy Corbyn struck a conciliatory tone – and according to a former shadow cabinet member present he gave one of his best speeches to date as he called on the party to come together. However, the announcement that Labour will support an amendment calling for a second referendum if its own amendment to change the government's negotiating position fails this week has proved divisive. While many MPs in the room welcomed the decision, even those who have campaigned for a second referendum were left frustrated. According to Owen Smith, Corbyn was asked 23 times if in a future referendum he would want Remain to be an option on the ballot paper. Corbyn declined to answer. Matters weren’t helped by a late night vote which meant the meeting came to an abrupt end. However, a briefing note has since been circulated among Labour MPs suggesting Remain would be on the ballot paper in the event of a second referendum.

Meanwhile, the announcement led to an angry response from those Labour MPs representing Leave seats. John Mann warned that Leave constituencies would never vote Labour if the party made a second referendum formal policy – telling Corbyn the move would stop him becoming prime minister. Caroline Flint added that a policy for a second referendum would not lead to 'unity in the party'. On exiting the meeting, Lucy Powell – the MP for Manchester Central – said she wasn't sure how she would vote if Labour whipped for a second referendum. Powell said she believes there are around 25 Labour MPs who would struggle to support such an action. MPs who are pushing for a soft Brexit – a Norway plus outcome – also spoke with concern about the developments. Stephen Kinnock said he had 'deep reservations' about the prospect of a second vote.

It's worth pointing out that even though the Labour frontbench have said they could support an amendment calling for a public vote when May returns with her deal, it's a pledge that comes with caveats. A Labour source says that the party would be reluctant to support the Kyle/Wilson amendment saying MPs will accept May's deal if it goes to a public vote as Corbyn does not want to be attached to anything that implies support for May's deal. If the wording changes, the amendment could become rather vague. So, what is the thinking behind Corbyn's latest Brexit position? A party source says Labour will do whatever it takes – by 'all the necessary means' - to prevent 'no deal' and May's deal. These are now Corbyn's Brexit red lines.