Sir Keir Starmer says that Labour has moved closer to backing a new Brexit referendum.

"We are now at the third phase of our policy. Make no mistake about it," the Shadow Brexit Secretary declared on Saturday.

Starmer said that Labour's failure to bring down the government this week left it with two options on Brexit.

The first is forcing Theresa May to accept Labour's Brexit deal. The second is backing a new referendum.

"That is a very important commitment. It’s a commitment to you, our members and our movement. And it is one we will keep," he told Labour Party members.

Labour leader Jeremy Corbyn is under pressure from MPs and party members to back what campaigners call a People's Vote.

Starmer also said it was "inevitable" that Brexit will be delayed.

LONDON — Shadow Brexit Secretary Sir Keir Starmer has declared that the Labour Party is one step closer to campaigning for a new referendum on whether Britain should leave the European Union.

Speaking at the Fabian conference on Saturday morning, Starmer told an audience of Labour Party members: "We are now at the third phase of our policy. Make no mistake about it."

The "third phase" refers to Labour policy of considering the option of a "public vote" on Brexit if the party is unable to bring down Theresa May's government and trigger a snap general election.

Labour leader Jeremy Corbyn tried to bring down the prime minister this week by laying a vote of no confidence in her government after her Brexit deal was rejected by a record-breaking House of Commons majority.

However, Conservative MPs and the Democratic Unionist Party put aside their criticisms of May's Brexit deal and rallied to her support, helping her defeat Corbyn's motion by a majority of 19 votes.

Starmer said on Saturday that while triggering a general election "always will be" Labour's desire, in the short-term the party has "just two remaining options left" on Brexit.

The first is to force May into accepting Labour's alternate Brexit deal of a "close economic relationship" with the EU based on permanent customs union, strong ties with the single market, and robust workplace and environmental standards.

However, if Labour cannot achieve this, then the party will honour its commitment to backing a new referendum, Starmer said.

"Our conference motion states that: 'If we cannot get a general election Labour must support all options remaining on the table, including campaigning for a public vote.'

"That is a very important commitment. It’s a commitment to you, our members and our movement. And it is one we will keep," he said on Saturday morning.

"I know there is significant support for this in our membership… In many trade unions. Among a number of Labour MPs….. in this city and – most likely – in this hall. As I set out in Liverpool, this has to be an option for Labour."

Jeremy Corbyn. Reuters

As Business Insider has reported, Corbyn's office is reluctant to commit to a new referendum because it believes to do so would alienate Leave-voters in seats that the party must in order to win the next general election.

However, the Labour leader is under growing pressure to back a new referendum — or what campaigners call a People's Vote — from at least 71 Labour MPs and the party's strongly pro-EU membership.

Labour MP Bridget Philipson, a supporter of the People's Vote campaign, told Business Insider: "Keir Starmer is sticking to both the letter and the spirit of Labour’s policy on Brexit by saying now is the right time for the party to begin campaigning for a public vote."

She added: "Labour’s members and supporters will not understand it if the party continues to hesitate at this moment of national crisis. After Parliament’s overwhelming rejection of the government’s deal, there is neither the time nor the patience for another game of fantasy Brexit.

"Instead, Labour needs to recognise that the only way any sort of deal gets over the line is probably with Labour’s official backing."

In his speech on Saturday, Starmer repeated his prediction in stronger terms that Brexit will be delayed.

"We also need to recognise that – whichever of these options we pursue – the March 29 deadline looks increasingly unlikely to be met," the Labour MP said.

"Even if the Prime Minister’s deal had been passed on Tuesday, there is a huge raft of legislation the Government would still need to pass.

A complex Implementation Bill. An Immigration Bill. Agriculture and Fisheries Bills. The Trade Bill. A Healthcare Bill. A Financial Services Bill.

"69 days. Six bills. Plus around 700 statutory instruments that still need to be passed. I don't think so."