UK opposition leader Jeremy Corbyn is to announce to MPs that the Labour Party will back a call for a second referendum on Brexit.

Parliament is due to debate and vote on several proposals and amendments on Brexit on Wednesday, including at least one that would demand that the exit deal is put to a public vote.

Corbyn announced that if Parliament rejects his party's Brexit plans this week, then the party will formally support another vote. While this is not a significant climb-down on previously announced policy, the change comes just a week after several members of the Labour Party left to start a fringe group over Corbyn’s perceived inaction in Brexit.

Labour said it would also put forward an amendment calling on the government to adopt its Brexit proposals.

Labour’s five demands for the Brexit deal are:

A permanent and comprehensive customs union with the EU

Close alignment with the Single Market underpinned by shared institutions and obligations

Dynamic alignment on rights and protections

Commitments on participation in EU agencies and funding programmes, including in areas such as the environment, education, and industrial regulation

Unambiguous agreements on the detail of future security arrangements, including access to the European Arrest Warrant and vital shared databases.

Labour's Emily Thornberry said that if Theresa May left Parliament with a choice between no deal or the Prime Minister's deal, then it should be taken to a public vote.

“Essentially we have been doing as instructed by our members unanimously. We went for, you know, we voted against, we went for a general election, we put all options on the table and then, you know, if we still can't get anywhere when we campaign for a people's vote with 32 days to go, we've now got to the end bit of that policy."

The party will also support a bid by Labour MP Yvette Cooper to give parliament the legal power to force May to seek an extension to the Article 50 negotiating period beyond the exit date currently set down in law — March 29.