After calling for a general election for two years, it is thought that the Labour leader would struggle to justify further votes against an early poll - particularly without the reason now being given, which is that Johnson could change the date of the election and have it take place after no deal.
A number of Mr Corbyn's colleagues want the party to unequivocally back Remain, but big backer the Unite union wants to ensure Leave is still an option.
DUP leader Arlene Foster and her deputy Nigel Dodds, who leads the party in Westminster, spent more than an hour inside 10 Downing Street and insisted they had enjoyed a "very good" meeting.
Although the debate ended without a vote and was not attended by the Prime Minister it was targeting, the session had been called by Labour MPs alarmed at the possibility the Prime Minister might find a way around a law they had passed to ban a full Brexit, forcing the nation to delay its withdrawal from the European Union once again. It may be ancient history to some of Labour's young new recruits, but many people will never forget how they supported terrorists responsible for horrific carnage in a brutal civil war which saw people blown up in pubs, hotels, and shopping centres.
His stance contrasts with Jeremy Corbyn's insistence on Tuesday that any referendum must include a "credible leave option", leaving the door open for Brexit voters to support Labour.
Addressing the annual Trades Union Congress conference, Mr Corbyn said he would reverse the "deliberate, decades-long transfer of power away from working people".
Mr Corbyn told the TUC he refused to agree to give voters a say because he did not want to allow Mr Johnson to "dictate" the terms.
In an address to union members in Brighton he pledged to "unleash the biggest people-powered campaign we've ever seen".
By contrast, 77% of Remain voters, 76% of Lib Dem voters and 69% of Labour voters all say that Johnson should refrain from breaking the law on this matter.
He warned that Johnson was pursuing a "Trump deal Brexit", and accused him of, "hijacking the referendum result to shift even more power and wealth to those at the top". "Once we get out of here, there isn't any way to establishment-up Jeremy", one Labour source said.
He also accused the PM of cosying up to President Donald Trump to get a "one-sided" trade deal with the USA which would damage employment rights, the NHS and United Kingdom industry. If there is still a majority for Brexit, what do they have to fear?
Deputy speaker Sir Lindsay Hoyle, who is also Labour, and veteran Tory MP Sir Edward Leigh earlier confirmed their intentions to stand.
The UK prime minister chose to send MPs home through October 14, but first tried to call a snap election to ensure his parliamentary majority, but the House of Commons twice opposed that proposal.