The British government has proposed a new version of the Brexit deal which the EU is considering.
The British government has proposed a new version of the Brexit deal, which the EU is considering. The two sides have agreed to "intensify" talks.
On 19 October for the first time this century MPs will sit in the House of Commons on a Saturday. That could be to vote on any deal, or to debate alternative routes ahead.
Boris Johnson's new proposal involves removing the backstop. That's the measure from the original withdrawal agreement aimed at preventing any possibility of border posts and checks between Northern Ireland and the Republic of Ireland.
The Irish border Brexit backstop
The deal negotiated by former prime minister Theresa May and her government was defeated in the House of Commons several times.
Mr Johnson's new idea is that Northern Ireland continues to follow EU rules and standards on all goods. That would remove the need for regulatory checks on goods crossing the Irish border.
However, Northern Ireland would stay in the customs territory of the UK. So there would be a customs border between Northern Ireland and the Republic. But the government's plan is that all customs checks could be made away from the border.
If the UK and EU can't agree a deal then under the so-called Benn Act the prime minister is obliged to request an extension of Article 50, delaying Brexit.
Cabinet ministers have said the government will obey the law, but the prime minister has said he will not ask for an extension. There has been some speculation about finding a loophole in the law or using some other device to avoid Mr Johnson himself having to ask for the extension.
For example, it's been suggested that he could request an extension but at the same time tell the EU to ignore his request.
If Mr Johnson refuses to write the letter asking for an extension then it's likely he will face a legal challenge.
Could a no-deal Brexit still happen on 31 October?
No-deal Brexit on 31 October
The default position is still that the UK will leave the EU on 31 October at 23:00 GMT.
Even if the prime minister requests an extension there is no guarantee that the other EU countries would agree.
Leaving without a deal (or withdrawal agreement) means the UK would immediately exit the customs union and single market - arrangements designed to make trade easier.
Many politicians and businesses say this would damage the economy. Others say the risks are exaggerated.
What is 'no-deal Brexit'?
Early election
An early election is widely expected after 31 October when Brexit is currently scheduled to happen.
That's because it takes at least 25 working days for an election campaign to take place.
If a Brexit is delayed, the House of Commons might be asked again by the government to back an early general election. That requires a 2/3 majority in the House of Commons and so far MPs have been unprepared to agree.
An alternative route for the government would be a short new law specifying the date of an early general election - this would require only a simple majority and not need two-thirds of MPs.
There is another much more dramatic way - the prime minister could call a vote of no confidence in his own government.
What are the PM's election options?
What is the Queen's Speech?
Vote of no confidence
At any point the opposition could call a vote of no confidence in the government. Labour leader Jeremy Corbyn has previously said he would table such a motion.
If more MPs vote for the no-confidence motion than against it, there would then be a 14-day window to see if the current government - or an alternative one with a new prime minister - could win a vote of confidence.
If no-one does then a general election would follow.
What is a vote of no confidence?
Cancel Brexit
There is also the legal option of cancelling Brexit altogether by revoking Article 50.
But clearly, this is not something the current government is contemplating - so it's only really possible to imagine this outcome after a change of government.
The Liberal Democrats have said that if they won a majority in the House of Commons they would revoke Article 50 and cancel Brexit.
