Jeremy Corbyn faces up to ten resignations from Labor's top team, if he can not enforce the case for a new Brexit referendum, it was reported.
Frustrated MPs are said to have warned the party leader that they are ready to resign unless he succeeds in voting for MPs for a referendum motion.
Labor has already tabled an amendment to the government bill, which stipulates that Theresa May either vote on a Commons vote by 27 February or give Parliament control of the process.
But now, anti-Brexit MEPs, shadow ministers and base members The Guardian have stated that they are ready to resign unless Mr Corbyn supports an amendment supporting a new referendum.
Mr. Corbyn was confronted in the party with conflicting views on whether a second vote should be supported. Some frontbenchers made it clear that they would not support an opposing vote.
Others, including Shadow Brexit Secretary Keir Starmer, said that the option of another referendum should not be ruled out.
Shadow Chancellor John McDonnell has insisted that the option of a new Brexit poll remains on the table and admitted that Labor's preferred scenario for speedy parliamentary elections seems unlikely.
The Labor leadership also wants to support a proposal from backer Yvette Cooper, which is expected to be debated on February 27, and will require a vote on the Brexit postponement by mid-March.
Commons spokesman John Bercow will decide which amendments will be voted on Thursday.
An amendment by Labor MEP Roger Godsiff calls for an extension of the Brexit negotiating period to allow a second referendum.
A bipartisan initiative backed by Labor's Tory Anna Soubry and Choura Umunna urges the government to release its latest official information on the impact of a no-deal Brexit on trade and commerce.
The SNP has submitted an application requesting the UK Government to open negotiations with the European Council immediately in order to extend Article 50 by at least three months.
It comes as Prime Minister saw the prospect of a Valentine's Day uprising against Tory's Hardline MP in an important Brexit poll on Thursday.
The Eurosceptic Conservatives are threatening to oppose a government proposal that, according to critics, means that Ms. May is giving up a no-deal exit option.