Labour Leader Jeremy Corbyn has admitted to ITV News that delaying the start of Brexit next March is an option.
He said if any deal the Government gets is not acceptable to his Party then they will vote against it.
When told by ITV News Political Editor Robert Peston it would be "inconceivable" for a General Election to be held, a Labour government formed and the party negotiate a different deal with the EU before the UK's agreed leaving date of March 29, 2019, Mr Corbyn said "all options" were there.
"We would negotiate" with the EU, the Labour leader said, adding that his party was "the one who put forward the transition period" in the first place.
Mr Corbyn refused to rule out anything, telling Peston: "All the options will be there."
Watch the interview in full
What are Labour's six tests which a Brexit deal must pass?
A “strong and collaborative” future relationship with the EU
The “exact same benefits” as single market and customs union membership
Fair management of migration
Defence of rights and protections
Protection for national security
Delivering for all regions and nations of the UK
Ahead of calling a General Election, Mr Corbyn said Labour would seek to send the "Government to go back and negotiate something better" with the European Union.
If they are unable to do this, they should "get out of the way and have an election so the country can make a decision on who it wants to handle the situation".
Earlier on Tuesday, shadow Brexit secretary Sir Keir Starmer told the Labour conference that if it were not possible to get a General Election, then Labour "must have other options".
Sir Keir won a standing ovation from a large majority of delegates, though some remained firmly in their seats.
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.
When asked if he was aware that Sir Keir would say that Labour is "not ruling out Remain as an option", Mr Corbyn insisted that he had seen the speech in its entirety before it was given.
"A speech isn't policy, the motion that is carried is," Mr Corbyn added.
During his interview, Robert Peston also questioned Mr Corbyn on the issue of anti-Semitism which has plagued the Labour Party all summer.
The Islington North MP told ITV News the issue was only with a "very small number of people acting in an anti-Semitic way" and that he had spent his "life as an anti-racist campaigner".
He continued that after asking Shami Chakrabarti to conduct an inquiry into any anti-Semitism in the Labour Party , "we have dealt with cases, I have ensured there is no delay in dealing with them and we're increasing the size of our national constitutional committee to ensure these things are done more quickly...
"Our party has adopted a very clear position on anti-Semitism and ensure there is an opportunity to have a debate on free speech on all these issues."
Mr Corbyn insisted the party had recognised the International Holocaust Remembrance Alliance position on anti-Semitism "from the beginning", and it was only the decision "to consult on the last few examples" which had caused a delay in the final decision from Labour's ruling body.
Robert Peston also questioned the Labour leader about claims made earlier this month by Andrew Murray, chief of staff to Unite union leader Len McCluskey, that because much of what Mr Corbyn's Labour Party proposes is perceived as anti-establishment, the secret services may be working to undermine him.
Mr Corbyn said this was not something that "kept him awake at night" and he "had not noticed" if intelligence services were working against him.
He continued: "Put it this way, what we're proposing - on a fund to invest in and their support, what we're proposing on co-operatives, would not be seen as radical in in much of Germany or Scandinavia."
Should a General Election be called following the possible failure of the Government's Brexit plan to pass through Parliament, or if Mrs May's administration served its full term, if Mr Corbyn fought and won at the polls, he would become the UK's oldest prime minister entering his first term.
However, the Labour leader said his age was of no concern to him: "I'm very fit, I'm very proud to lead our party, and I'll do exactly that because I want to bring about that social transformation, I want to give real hope to young people and those who are up against it in our society."
As a hypothetical Prime Minister, how would Mr Corbyn know when he had achieved everything he set out to: "When we'd achieved it", he replied.