Members of Parliament (MPs) have taken control of the agenda in parliament today, and are voting this evening on a new law that would force Prime Minister Boris Johnson to have to ask for an extension to the Brexit deadline, if he can't get a deal.
To become law the proposal has to pass through various stages in Parliament and be given the stamp of approval by the Queen.
A group of MPs in the House of Commons - made up of politicians from different political parties, including Mr Johnson's own party - want to delay Brexit and force the government to ask for an extension to the 31 October deadline that is currently in place (and which the prime minister wants to stick to).
It's because they want to make sure that the UK can't leave the European Union with no deal at all, as they feel it would be bad for the UK.
Prime Minister Boris Johnson and many of his colleages disagree - they argue that the best way to get a good deal from European leaders is to have the option to walk away.
He has said that he is not prepared to ask for an extension and his team say that if the bill passes, then Mr Johnson will call for a general election.
The leader of the Labour Party Jeremy Corbyn has said that the bill needed to be passed to take the no-deal option completely "off the table" before his party would support the call for a general election.
Under the Fixed Term Parliaments Act, Mr Johnson will need to have the support of at least two-thirds of MPs in order to call his election.
Losing the vote would be a major blow for the new prime minister, who has kicked some of his own MPs out of the Conservative Party because they have voted against him.
But it wasn't the only thing that didn't go to plan for him yesterday.
Yesterday evening, an MP from Mr Johnson's own Conservative Party, Phillip Lee, switched teams and walked across the House of Commons to join the Liberal Democrat Party. This is called 'crossing the floor'.
It was particularly significant as it means that the prime minister no longer has the majority of support in Parliament, making it more difficult for him to get MPs in Parliament to vote in favour of what he wants to do.