With weeks until the 31 October deadline, how can the UK avoid crashing out of the EU?

There remain several routes for the UK to avoid a no-deal exit from the EU on 31 October.

When parliament returns on 3 September, one of the first key decisions will be whether the Labour leader, Jeremy Corbyn, calls a vote of no confidence in the government.

His meeting with opposition leaders initially seemed to favour legislating their way out of no deal rather than trying to bring down the government, but the prime minister’s decision to suspend parliament may have significantly changed that thinking.

If Jeremy Corbyn wins a vote of no confidence in Boris Johnson

If Corbyn can get enough votes to pass a no-confidence motion in Boris Johnson, which will mean persuading at least some Conservative MPs to vote against their own government, he and the opposition will have 14 days in which to assemble an alternative majority.

Corbyn has said he would be willing to run a caretaker administration, with the express purpose of asking the EU for a further extension to article 50 and then calling a general election.

During that time, MPs may also seek to legislate that it is mandatory to extend article 50 rather than leave without a deal. And if Corbyn, or anybody else, is unable to form an administration that can command a majority of MPs supporting it, there will be a general election in any case.

That does not, however, permanently rule out a no-deal Brexit – there is no guarantee what the result of that election would be.

If Corbyn does not call, or does not win, a vote of no confidence in Johnson

The alternative is that Johnson does not face – or wins – a vote of no confidence. The timetable would then proceed along the lines that the prime minister has set out. Parliament will be suspended during the week of 9 September and negotiations with the EU can continue during the party conference season.

On 14 October, MPs will return to the House of Commons for a Queen’s speech setting out Johnson’s domestic priorities. Three days later, Johnson will go to a European council meeting of the EU27, at which he would want them to agree a new deal. If the EU does not agree a new deal, the legal default is still that the UK would leave the bloc on 31 October without a deal.

Q&A What does a no-deal or WTO-rules Brexit mean? Show Hide If the UK leaves the EU without a deal it would by default, become a “third country”, with no overarching post-Brexit plan in place and no transition period. The UK would no longer be paying into the EU budget, nor would it hand over the £39bn divorce payment. The UK would drop out of countless arrangements, pacts and treaties, covering everything from tariffs to the movement of people, foodstuffs, other goods and data, to numerous specific deals on things such as aviation, and policing and security. Without an overall withdrawal agreement each element would need to be agreed. In the immediate aftermath, without a deal the UK would trade with the EU on the default terms of the World Trade Organization (WTO), including tariffs on agricultural goods. The UK government has already indicated that it will set low or no tariffs on goods coming into the country. This would lower the price of imports – making it harder for British manufacturers to compete with foreign goods. If the UK sets the tariffs to zero on goods coming in from the EU, under WTO “most favoured nation” rules it must also offer the same zero tariffs to other countries.

WTO rules only cover goods – they do not apply to financial services, a significant part of the UK’s economy. Trading under WTO rules will also require border checks, which could cause delays at ports, and a severe challenge to the peace process in Ireland without alternative arrangements in place to avoid a hard border.

Some no-deal supporters have claimed that the UK can use article XXIV of the General Agreement on Tariffs and Trade (Gatt) to force the EU to accept a period of up to 10 years where there are no tariffs while a free trade agreement is negotiated. However, the UK cannot invoke article XXIV unilaterally – the EU would have to agree to it. In previous cases where the article has been used, the two sides had a deal in place, and it has never been used to replicate something of the scale and complexity of the EU and the UK’s trading relationship. The director general of the WTO, Roberto Azevêdo, has told Prospect magazine that “in simple factual terms in this scenario, you could expect to see the application of tariffs between the UK and EU where currently there are none”. Until some agreements are in place, a no-deal scenario will place extra overheads on UK businesses – eg the current government advice is that all drivers, including lorries and commercial vehicles, will require extra documentation to be able to drive in Europeif there is no deal. Those arguing for a “managed” no deal envisage that a range of smaller, sector-by-sector, bilateral agreements could be quickly put into place as mutual self-interest between the UK and EU to avoid introducing or to rapidly remove this kind of bureaucracy. Martin Belam

If the EU does agree a new deal, Johnson would have a few days for MPs to debate and agree to it. The UK would then leave the EU with a deal, and all the signs are that Johnson would most likely call a general election shortly afterwards.

If MPs do not pass the deal – they rejected Theresa May’s withdrawal agreement three times – then the UK would again default to leaving without a deal on 31 October.

It is important to note, of course, that whatever the outcome on 31 October, this will not be the end of Brexit by a long stretch. The deal only sets out what happens during a transition period, during which the government will want to negotiate a new free-trade agreement with the EU.