Prime Minister Theresa May has agreed a Brexit deal with the EU, but the UK parliament still has to have a say.
On December 11, after five days of debate, it decides.
If a majority backs the deal, the UK will leave the EU on May 29, 2019, but Mrs May needs 320 votes and most analysts say she’s way off.
Tim Marshall from The National's London bureau explains some of the No vote scenarios Theresa May and her party will face.