LONDON (BLOOMBERG) - The UK Labour Party is calling for a vote in Parliament that could pave the way to a second referendum, raising the possibility that Brexit could be reversed.

The main opposition party proposed an amendment to a government motion - due to be debated on Jan 29 - calling for votes on various ways of avoiding a messy no-deal divorce. One of those options is a second referendum.

The amendment is signed by leader Jeremy Corbyn, who has so far been equivocal about his support for a second referendum. If he does throw his weight behind another ballot - which is still to be confirmed - it could be decisive. About 10 Conservative members of Parliament are already campaigning for another plebiscite.

Two years since the first referendum, the UK has yet to negotiate an exit accord that can win the backing of Parliament. Mrs May's deal was rejected by lawmakers last week by a historic margin and she is now trying to revise the agreement with the EU to win over opponents at home.

"Our amendment will allow MPs to vote on options to end this Brexit deadlock and prevent the chaos of a No Deal," Mr Corbyn said in an e-mailed statement.

"It is time for Labour's alternative plan to take centre stage, while keeping all options on the table, including the option of a public vote."

This proposal is the furthest Mr Corbyn has gone towards backing another national vote and the first time his Labour party has put the option forward for lawmakers to consider.

The formula of "keeping all options on the table" echoes a compromise deal agreed by the party last year that has enabled Mr Corbyn to hold off demands from rank-and-file members and lawmakers to support a second plebiscite.

"This is a huge step forward and shows the Labour leadership's commitment to stop a disastrous no deal exit," said Mr Mike Buckley, director of Labour for a People's Vote.

"We still need clarity on Labour's position in a public vote and whether, as members want, we would campaign robustly for our continued membership of the EU."

On the EU side, a second referendum would be welcomed by many, and it would almost certainly mean an extension to exit day, which is now scheduled for March 29. The pound was unchanged.

THREAT TO DEMOCRACY

Prime Minister Theresa May rejected calls for a second referendum from MPs on all sides of the house during an appearance in the House of Commons on Monday (Jan 21), warning it would "damage social cohesion by undermining faith in democracy". She said it would break the trust of the 17.4 million voters who backed leaving the EU.

Mrs May also said she does not believe there is a majority for a referendum in the House of Commons.

The Labour move might just play into Mrs May's hands. Pro-Brexit hardliners in her party could decide that the deal she negotiated - though they hate it - is a better option that risking a re-run of the referendum that could reverse the decision of 2016. Some in Labour's ranks are also uncomfortable with the prospect of asking voters to think again.

The Labour amendment calls for lawmakers to be given a vote on options including the opposition party's alternative plan for a permanent customs union with the EU and a strong relationship to the bloc's single market. If that is not accepted then their should be a referendum on any deal that is agreed by the House of Commons, it says.