After weeks of negotiations that seemed to be going nowhere, another deal was struck on Thursday.
The EU’s top negotiator declared the backstop has been abolished. But not everyone is happy with the replacement.
The new deal means Northern Ireland will stick to some EU rules, while technically still being in the UK customs area. Crucially, some checks will still take place between Britain and Northern Ireland.
Four years after it comes into effect, Northern Ireland’s politicians will have a say on whether to keep the deal going.
The EU is expected to agree to the new deal, if Ireland is happy.
Mr Johnson has until Saturday 19 October to get his deal across the line in the UK Parliament – or else he is legally required to request an extension to Brexit.
MPs in London will decide whether to sit on Saturday to debate the deal in the first Saturday session since 1982 – and that was at the start of the Falklands War.