Labour's vote was welcomed by the Best For Britain campaign for a second referendum, whose chief Eloise Todd said: "Today is a game-changer for the campaign to give the people the final say on Brexit".
Speaking to the BBC, Mr Corbyn said he did not know what the deal would look like, but if it was rejected by MPs, the government "will have to go back to the European Union and say "our parliament can't agree to this". In the United Kingdom that means a vote by lawmakers, and the math looks ominous for May's minority government.
"What we've said all options must be considered if and when this government collapses or its negotiations collapse - the options are still there".
The party will debate and vote on a motion to remain in the bloc on the table if a General Election can not be triggered by Labour.
Tiger Woods ends five-year title drought with Tour Championship triumph
October 30, 2015: Woods reveals he has undergone a "follow-up procedure" to September's surgery. Woods now goes to France, where he'll play in the Ryder Cup with the rest of his US teammates.
When asked by Sky News presenter Niall Paterson whether it would be "undemocratic" to consider the possibility of reversing the result of the Brexit referendum, the shadow business secretary launched into a furious rant.
But with May's plan for maintaining close ties with the European Union for trade in goods facing opposition from her own lawmakers, she is aware of the crucial role Labour could play in getting a deal through parliament.
His declaration that "nobody is ruling out Remain as an option" was not included in printed copies of his speech distributed to the media, sparking speculation that he may have gone beyond the position agreed by Labour's high command.
Delegates at the party conference in Liverpool, north-west England, voted overwhelmingly for a motion that calls for a second referendum in the event that parliament fails to approve an eventual deal.
"It would not be in the national interest to have an election", May told reporters on board her official plane en route to NY, where she will attend the United Nations General Assembly.
Beluga whale spotted in River Thames
Belugas (file picture), also known as white whales, are known for having rounded foreheads and no dorsal fin. In 2006, a northern bottle-nosed whale up to 18ft-long (5m) became stranded in the Thames for two days.
But May is sticking by her proposal, saying the "hard Brexit" proposed by some Conservatives would be "a bad deal" because it would not resolve the Irish border problem.
"This isn't about frustrating the process", he said.
Asked if she wanted an apology, she replied: "What I welcome is the fact we have seen Donald Tusk following our response, we have seen Donald Tusk actually clarify the position that they were taking and make it clear that actually the European Union side does want to look at a deal". If they don't meet our six tests, we will vote against it, and then we will take it from there.
"I am confident we can reach a deal about our future relationship".
"Of course, to a significant extent, this also depends on what Britain really wants - the discussion isn't so clear here", she said.
Storms predicted Tuesday could produce hazardous weather
According to The Weather Network's latest forecast , Quebec is at a high-risk for severe weather for tonight and Wednesday . East winds at 7 to 12 miles per hour ahead of the warm front will shift to the south after the front passes by.