- 17:30, 28 JUN 2018
- UPDATED17:32, 28 JUN 2018
Britain has voted to leave the European Union, and it'll affect all our lives.
As things stand, Brexit will come into force at the end of March 2019.
But it could be 2022 before you notice any difference - and the path to the door is littered with obstacles.
Some believe Brexit can be stopped. Others fear it could bring down the Government.
Theresa May has only a few months to strike a deal.
She has to get the EU Withdrawal bill through, negotiate the future with Brussels, get her Cabinet to agree and keep the peace in the Tory Party.
Meanwhile the whole saga is so fiendishly complicated it risks leaving you in the dark.
So here is your guide to what is going to happen, what the key issues mean, and the dangers that lie ahead.
What is Brexit?
Brexit is Britain's exit from the European Union.
The UK voted 52%-48% in 2016 to leave the 28-nation body after almost 50 years.
That means leaving its single market and customs union (see below), cutting legal ties, ending the automatic right for EU citizens to move to Britain, and reducing or ending budget payments to Brussels.
What are Hard Brexit and Soft Brexit?
Hard Brexit means cutting major ties with the EU and striking out alone, even if it damages the economy. This is backed by a large number of Tory MPs and UKIP.
Soft Brexit means sticking as close to EU rules as possible, even if it means giving up freedom and independence. This is backed by a large number of Labour MPs, and a few Tory rebels.
The Cabinet and the Tory party are split and Theresa May is trying to go for something in between to please everyone. So is Jeremy Corbyn.
When does Brexit happen and when is the deadline?
Britain officially leaves the EU at 11pm on 29 March 2019.
However a transition period has been agreed, which means almost all current rules continue until New Year's Eve 2020.
Then there is also a customs 'backstop' (see below) which could continue EU rules into 2021, or even 2022.
However, the deadline to agree the main deal is around October 2018, because it needs time to be agreed by MPs and the European Parliament.
What is the divorce bill?
Britain's Brexit 'divorce bill' - the amount it'll pay after March 2019 - was finally revealed some 534 days after the country voted to leave the EU.
Downing Street said the figure would be 40 to 45billion Euros - or between £35billion and £39billion.
The huge sum came despite Boris Johnson previously accusing the EU of "extortion" and claiming they could "go whistle".
Brexiteers promised to win back £350million a week for the NHS.
However, the £350million was never going to come back in full because large amounts of it never actually went to Brussels in the first place.
What is the transition period?
Britain has secured a 'transition period' to achieve a smooth Brexit and give businesses certainty.
This will give us time to prepare for life outside the EU, such as setting up new customs systems and agencies.
But it means Britain has to continue to accept EU rules, including freedom of movement (EU immigration), and European Court of Justice jurisdiction.
Britain and Brussels agreed the transition in December 2017. The key details are explained below.
What deal does the government want?
That is the £350million-a-week question. The Cabinet hasn’t decided.
The EU said we had two choices, the Norway model or the Canadian model, but Theresa May essentially ruled both out.
The Norway option (EEA) would see us paying to access the single market and accepting EU rules, including free movement of people.
The Canadian-EU agreement (CETA) allows for free trade between the two countries but does not include services which is our largest sector.
The Prime Minister claims she will get a bespoke deal for Britain - sometimes called 'Canada Plus'.
This will be a free trade arrangement with frictionless borders and include financial services.
In other words we want a huge array of the benefits of being in the club - but without paying a membership fee.
How are the Tories split?
The Tory Cabinet is split on how closely it will align with EU rules after Brexit.
Chancellor Philip Hammond wants us to stay close to the EU to avoid adding red tape and customs delays.
But Brexiteers like David Davis, the Brexit Secretary, believe this will limit our ability to strike competitive trade deals with non EU countries.
There is a powerful Hard Brexit wing on the Tory benches. More than 50 MPs are in the European Research Group, a pressure campaign led by influential MP Jacob Rees-Mogg.
There are fewer Hard Remain MPs on the Tory benches, but they have a huge amount of power because Theresa May has a very thin majority. That means if they team up with a united, Labour they can defeat the government.
How is Labour split?
Labour's leadership says Britain should have a full Customs Union with the EU (see below) but leave the EU single market (also see below).
There is an angry wing of about 50 Labour MPs who say leaving the single market is the wrong decision, and often rebel against Jeremy Corbyn.
Slowly, they have helped persuade the party leader to shift Labour's stance towards a 'soft' Brexit - hence the customs union policy.
Can Brexit be stopped?
At the moment this looks unlikely.
There are campaigns with multi-million pound backing, such as Best For Britain, that are trying to halt the process as we know it.
But stopping Brexit would probably need a second referendum. And we'd need a big change in public opinion to make the pressure hot enough to get one.
Most polls have yet to detect any significant shift since the June 2016 referendum, with those who voted Remain still likely to vote Remain and those who voted Leave still likely to vote Leave.
Both Tory Boris Johnson and Labour's John McDonnell have warned of a public backlash if there was any attempt to overturn the referendum result.
Some diehard pro-EU campaigners still believe it is possible to reverse the decision - but most are focusing on trying to stop a hard Brexit.
The House of Lords tried to do this through the EU (Withdrawal) Bill, where peers passed 15 amendments turning Hard Brexit to Soft. But they were overturned by MPs.
Labour has insisted it is not backing a second referendum. But several times, senior Labour figures have refused to rule out backing one in future. And many backbench MPs openly back a second referendum, calling it a 'People's Vote'.
What will happen to EU citizens?
Britain and Brussels have agreed EU nationals can continue arriving, working and settling in the UK until December 2020.
This will also apply the other way round.
But it's not known what rights people will get if they arrive after that.
It's been suggested EU citizens will get preferential immigration rights compared to people from the rest of the world, but that's not confirmed.
What about EU citizens who live in Britain now?
More than 3million EU citizens already live in the UK. They spent months not knowing what would happen, but now it's confirmed.
During 2018, the Home Office will launch an application system for EU nationals seeking to remain in Britain after Brexit.
Those who have been in the country for five years by the end of 2020 will be able to apply for "settled status" - meaning they are free to continue living and working in the UK.
People who have arrived by December 31, 2020, but do not have five years' residence, will be able to apply to stay until are eligible to apply for the status.
What about British citizens who live in the EU now?
More than 1million British citizens live in the other 27 EU countries.
They will have the same rights to stay there as EU citizens have to stay in the UK.
But it's not clear if they'll lose the right to move around and settle in any of the other 26 EU countries.
Perhaps for this reason, applications for foreign citizenship - especially in Germany - have soared since the Brexit vote.
What is the single market?
The single market is the EU's united system for trading and exchanging without any borders between 28 nations.
Theresa May has insisted we will leave it after Brexit.
It has many benefits, but in order to stay in it we'd have to sign up for four 'freedoms' - the free movement of goods, services, people and capital.
This would leave Britain unable to crack down on immigration.
What is the customs union?
The European Union operates as a 'customs union'.
This means the 28 member states can trade freely with each other without any checks or duties on goods.
It also means all the countries in the EU set the same tariffs on imports from non-EU countries.
For example, car imports from the US to the EU carry a 10% tariff, while South Africa has to pay up to 16% on the oranges which it exports to the EU.
Being in the customs union benefits the UK because the EU is our largest trading partner.
But Theresa May wants the UK to leave the customs union, because otherwise we can't sign trade deals with other countries around the world.
What are the two options for customs in future?
The government has been considering two options for customs, and has not chosen which one it'll stick with yet.
Customs partnership: This would see Britain collect tariffs on all imports on behalf of the EU. If the UK tariff is lower than the EU one, then firms would be able to reclaim the difference. This is favoured by Remainers, but Brexiteers including Boris Johnson say it is "crazy" and will shackle us to Brussels.
Maximum Facilitation ('Max Fac'): This would introduce more checks, but use high-tech tracking devices to monitor the flow of goods. Businesses would operate as “trusted traders” and would be able to pay any tariffs at regular intervals rather than every time they cross a border. Boris Johnson wants this, but the civil service say it will cost firms £20bn a year in red tape.
Why is Northern Ireland such a big problem?
Northern Ireland is the problem that's been holding up almost all the talks.
That's because it is the UK's only land border with the EU - the Republic of Ireland.
And to make things a lot trickier, Northern Ireland can't just stick a wall up along that border. It has all kinds of special statuses because of its violent history.
The 1990s Good Friday Agreement finally ended the Troubles by banning border checks between Northern Ireland and the Republic.
Theresa May has vowed not to bring these checks - a 'hard border' - back, otherwise she risks a return to violence.
Yet she also wants to bring in a totally different set of customs and trading rules for the UK compared to the EU.
So how does she change the rules in Northern Ireland without isolating it from the Republic?
Two years after the Brexit vote, people are still struggling to work it out.
What is the customs 'backstop' and why is everyone fighting over it?
What other problems are there?
The negotiations are not just about trade. The UK and the EU have to discuss data sharing and data protection, regulatory alignment and procurement rules.
Decisions have to be taken on whether we remain in some EU agencies such as Europol, European Medicines Agency and the European Aviation Safety Agency.
Then we have to agree police and intelligence co-operation on issues such as the European Arrest Warrant, criminal records sharing and freezing criminal assets.
Is that all?
No. The UK also has to work out trade arrangements with countries that currently have trade deals with the EU.
Britain would like to roll over these trade deals during the transition period.
The problem is that is not in our gift.
While some of these countries have signalled they are willing to rollover the trade agreements, others such as South Korea and Chile are more reluctant.
India, for instance, could demand we grant more visas in return for a deal.
They have sensed an opportunity to exert some leverage on the UK.
When will it come to ahead?
The moment of maximum danger for the Prime Minister will be in October.
This is when MPs will have the opportunity to vote on any deal.
Nothing is certain. It could be the EU and the UK have been unable to reach a deal by this time and will ask for extra time.
This would require the Article 50 deadline of March 2019 to be extended - something which would require the agreement of all 27 EU countries.
It is also unclear if MPs will have the opportunity to send Mrs May back to the negotiating table if they dislike the deal or they will be presented with a take-it-or-leave it deal.
If it is the take-it-or-leave-it option and the Prime Minister lost the vote then we would crash out without a deal.
It could also force the resignation of the PM or, possibly, oblige her to call a second referendum.
Alternatively, MPs could vote to send Mrs May back to the negotiating table which could see the talks delayed beyond March 2019 - again this would require the EU27 to accept an extension to Article 50.
