The pressure is on for MPs to give their backing for a deal before the latest Brexit deadline of October 31.
With so much disagreement, it creates more questions than answers but here are the burning issues and simple queries which are on the British public's mind:
- Starting with a simple one, what is Brexit?
“Brexit” is a slang term meaning “British exit”. It covers Britain’s departure from the European Union, which the public voted for in a referendum in 2016.
- When is Brexit?
The UK is due to leave the EU by 31 October.
The original leave date was planned for 29 March but a no deal agreement in Parliament allowed for an extension until autumn.
However, if an agreement is reached in parliament for a deal before then, Britain can leave the EU ahead of the deadline.
There is a transition period after this date until 31 December 2020 - or later - to prepare for the agreed changes.
- Is Brexit cancelled?
Brexit is not cancelled. A large majority of MPs disagreed with Theresa May’s government about the best way to continue, and a sizeable minority of MPs have argued for a second referendum - but at present the UK is due to leave the EU by October 31.
A petition to revoke Article 50 gathered more than six million signatures, however, the government said responded to say they would honour the 2016 referendum.
- What is a no-deal Brexit?
This means that Britain will no longer be part of the EU and will have left without provisions in place or a transition period.
The government is in the process of negotiating the terms of the latest deal and if an agreement is not reached before the deadline, Britain will leave the EU with a 'no-deal'.
- What is the withdrawal agreement?
Theresa May presented her 585-page withdrawal agreement outlining the plans for future EU and UK relations.
The prime minister's original deal was defeated in Parliament under the "meaningful" votes earlier this year.
So far there have been two "meaningful" votes on the prime minister's deal and one vote on part of her deal. All have failed to win majority support.
- What happened with Brexit?
After more than a year of negotiations, Mrs May presented her EU Withdrawal Agreement to Parliament in November, but it was immediately dismissed by hard Brexiteers within her own party, leading to a string of Cabinet resignations.
Hours before Parliament was due to vote on the deal in December, sensing a heavy defeat, the PM delayed the vote and returned to Brussels to seek reassurances about its implications.
Despite her efforts, MPs rejected the deal in a meaningful vote earlier this year.
Mrs May later brought Labour leader Jeremy Corbyn into discussions to help break the Brexit deadlock.
- Will Theresa May stay leader?
Senior Tory activists will consider the question of Mrs May’s leadership at an emergency meeting of association chairmen – set for Saturday, June 15.
Theresa May's leadership was questioned last December when MPs voted on whether or not to remove her as leader.
The prime minister won her no-confidence vote and another vote cannot be triggered for a 12 month period under the current rules.
The ex-UKIP leader Nigel Farage announced his involvement in the new Brexit Party as leader in April.
The party was founded earlier this year under financial trader Catherine Blaiklock but she resigned from the role after criticism over comments and tweets described as islamophobic. Although he stepped back from UKIP to be an independent MEP, Nigel Farage said he was "ready for battle" ahead of the European Parliament elections.
They are in the process of recruiting for a future general election and put forward several candidates for May's European elections.
Among the Brexit Party candidates announced were former MP Anne Widdecombe, James Glancy, a Royal Marine veteran; former charity boss Matthew Patten; former nurse Christina Jordan; and smoked salmon producer Lance Foreman.
- How much has Brexit cost so far?
The government set aside more than £4.2 billion for Brexit preparations in 2016, not all of which has been spent yet.
A study by the Centre for European Reform in September found the UK economy was 2.5% smaller than it would have been had Remain won the referendum.
The centre’s deputy director, John Springford, estimated the impact to have cost the Treasury roughly £440 million per week - and Cost Of Brexit has set up a running total, currently totalling over £60 billion.
- What is the customs union?
The EU’s customs union is a common agreement which allows all 28 members of the bloc to trade goods with each other without paying a tax on imports.
The rules mean each country charges the same import taxes on countries outside the EU who wish to import goods, and allow for any goods that have been imported into an EU country to pass through the bloc without any further checks.
- What is WTO Brexit?
Many Brexiteers who support leaving the EU without a deal have argued that a simple solution would be for the UK to trade with the rest of the world on rules set by the World Trade Organisation.
WTO rules decide the level of tax imposed on goods whenever they cross a border, known as tariffs, where countries do not already have an agreement.
There are no tariffs on UK imports from the EU, and tariffs on imports from other countries are relatively low thanks to existing trade agreements.
Trading under WTO rules means tariffs will be much higher.
The UK has yet to negotiate any new trade deals with any other countries in preparation for leaving the EU, meaning WTO rules would apply to all imports and exports.
Until new trade agreements are signed, anything imported into the UK or exported but UK businesses will be subject to these much higher taxes, damaging businesses and affecting the prices of nearly all goods found in the shops.
- What is the backstop in the Brexit negotiations?
The backstop arrangement outlined in the Prime Minister’s deal would create a single EU-UK customs area to ensure there is no hard border on the island of Ireland.
This means the UK would continue to follow the EU’s tariffs and rules on customs, avoiding the need for checks between the EU and UK - including Northern Ireland and the Republic - until a new relationship is decided.
Northern Ireland would need to follow some of the EU’s single market rules - including laws on goods, agricultural production, veterinary controls and state aid rules.
It is this point that led many - including Northern Ireland’s Democratic Unionist Party and a number of Conservative backbenchers - to oppose the deal.