Theresa May has told MPs "95%" of the UK's divorce deal with the EU has been agreed.
The prime minister has hailed the progress in negotiations despite a final agreement with Brussels still eluding her.
Time is running out for an emergency EU summit to be held this month for the bloc's leaders to approve an agreement.
This has prompted reports the UK will soon need to enact "no-deal" Brexit preparations.
So, what remains to be negotiated?
:: IRISH BORDER BACKSTOP
Even at this late stage in the negotiating process, the issue of the Irish border continues to act as a blockage.
Both the UK and the EU are committed to the idea of a backstop solution to prevent a hard border on the island of Ireland, should a future UK-EU trade relationship not avert this.
But, both sides remain at loggerheads over their competing backstop proposals.
Mrs May is adamant Northern Ireland should not in any way be split off from the rest of the UK after Brexit, as Brussels has suggested; while the EU are resisting Britain's demand for any backstop solution to be time limited.
Both sides are negotiating on a UK-wide backstop arrangement, which would see the whole UK remain in an effective customs union with the EU.
However, a leaked letter from the prime minister revealed Brussels are still pushing for a Northern Ireland-only solution as a "backstop to the backstop".
Pressure has also come on Mrs May to negotiate an ability for the UK to unilaterally withdraw from a backstop arrangement.
The Republic of Ireland has rejected this, but has said it is open to a review mechanism being written into a backstop deal.
:: THE FUTURE RELATIONSHIP
Mrs May's claim that 95% of the Brexit deal is complete only applies to the UK's withdrawal agreement, with the EU having yet to show any sign of dropping their resistance to the prime minister's Chequers plan for the future UK-EU relationship.
Despite the prime minister hailing "important progress made on issues like security, transport and services", Brussels has previously told Mrs May her plans for an economic partnership based on a "common rulebook" and a "combined customs territory" will not work.
Alongside the withdrawal agreement, the prime minister will present MPs with a political declaration on a future relationship.
Labour have warned they will vote against a "blind" Brexit, in which the terms of the new relationship are vague and left for continuing negotiations during the Brexit transition period, scheduled to last until the end of 2020.
Pro-Remain MP Chris Leslie, who wants a second Brexit referendum, believes the prime minister's suggestion a Brexit deal is 95% complete is "utter misrepresentation" and "designed to make you think Brexit is nearly over".
The former Labour minister added a withdrawal agreement is "merely clearing of the throat" before "arduous" trade deal negotiations lasting, Mr Leslie suggested, more than a further five years.
And, what has already been settled?
:: CITIZENS' RIGHTS
In a draft of the UK's withdrawal agreement published in March, the issue of the rights of EU citizens living in Britain and UK citizens living in the EU was said to have been finalised.
Mrs May has since guaranteed the rights of EU citizens in the UK even in the event of a "no-deal" Brexit.
:: DIVORCE BILL
In the March draft agreement, the UK's financial settlement was also marked in green to imply it has been settled.
The Treasury estimates Britain's divorce bill will cost between £35bn and £39bn.
However, the prime minister has suggested she could reconsider handing over the cash if there is no overall deal with the EU.
:: TRANSITION PERIOD
The so-called "implementation period" - otherwise known as the Brexit transition period - was also marked in green back in March.
It has been agreed the UK will maintain the status quo of EU membership between the date of Brexit on 29 March next year, and 31 December 2020.
The government argues this will mean businesses will only need to make one set of changes required by Brexit, as new trade relationships are negotiated and put into place.
Mrs May has since opened the possibility of the transition period being extended beyond 21 months as she struggles to solve the Irish border issue.
The UK and Spain have "developed a protocol and a set of underlying memoranda relating to Gibraltar, heralding a new era in our relations", according to the prime minister.
The issue of Gibraltar's sovereignty, which has long been disputed by Spain, had been expected to be a key flashpoint in Brexit talks.
Soon after the Leave vote in 2016, then Spanish foreign minister Jose Manuel Garcia-Margallo claimed Brexit "opens up new possibilities" for Spain to take control of Gibraltar, adding: "The Spanish flag on 'the Rock' is much closer than before".
However, the status of Gibraltar after Brexit appears to have been settled without further tensions between London and Madrid.
The UK and EU have agreed a protocol relating to two British military bases in Cyprus.
They have remained on the Mediterranean island since Cyprus's independence from Britain.
:: NOTHING IS AGREED UNTIL EVERYTHING IS AGREED
A mantra often quoted in EU negotiations portrays how any one part of the withdrawal deal unravelling could lead to a whole agreement falling apart.