Brexit is back on the agenda - three years after Boris Johnson insisted he had got it done.
The UK formally severed its ties with the EU in 2020 after years of bitter wrangling but the future relationship with Brussels is very much not resolved.
Mr Johnson tried to pick apart a key element of the Brexit deal - which he signed - governing trade in Northern Ireland, triggering a major backlash from the EU.
Under his leadership and his successor Liz Truss, the Tory Government was accused of trying to break international law by trying to ram a new bill through Parliament to scrap parts of the deal without EU agreement.
But this legislation has been put on ice by Rishi Sunak who is trying to agree a new deal with EU leaders.
Murmurs have been coming out of London and Brussels in recent days that an agreement is close - but No10 is remaining tight-lipped at the moment.
The Prime Minister's official spokesman said today that there was not yet a "final deal".
The path ahead is littered with political landmines, with Boris Johnson lurking in the wings, and Tory Brexiteers and the hardline Democratic Unionist Party (DUP) for the PM to win over.
Here's what's going on and why Brexit definitely isn't done.
Why are we still talking about Brexit?
Boris Johnson promised voters an “oven ready” Brexit deal at the 2019 election, but the trading arrangements for Northern Ireland have led to continued rows.
The UK and EU have been locked in talks on how to fix them for over a year, but it is hoped an agreement could finally be sealed this week.
Foreign Secretary James Cleverly, Northern Ireland Secretary Chris Heaton-Harris and the European Commission's Maros Sefcovic will hold talks by video link this afternoon, fuelling speculation that an agreement is close.
What is the Northern Ireland protocol?
As part of the Brexit negotiations, the two sides agreed the Protocol, which was designed to avoid the need for a border between Northern Ireland - which left the EU along with the rest of the UK - and the Republic of Ireland - which remains in the bloc.
But this has led to disruption on goods crossing the Irish Sea, with new checks imposed on those moving to the province.
Preventing a hard border on the island of Ireland has been a critical stumbling block throughout the Brexit process.
The legacy of the Troubles means that physical infrastructure such as checkpoints would be inappropriate, triggering warnings that it could lead to a return to violence.
Protecting peace in Northern Ireland is the absolute priority for all sides - and a key concern of US President Joe Biden, who is proud of his Irish heritage.
Who is unhappy?
Concerns have been raised by unionists that Northern Ireland's place within the UK is being undermined, with the Democratic Unionist Party blocking the formation of a power sharing executive at Stormont until the issue is resolved.
This means Northern Ireland has effectively been without a functioning Government.
Hardline Tories are also said to be unhappy, with reports that more than 100 MPs could rebel against a new deal with the EU.
Mr Sunak could survive this sort of rebellion by relying on Labour's votes but it would be bruising for his authority - and could lead to future problems.
Downing Street has refused to say whether MPs will get a vote on any new deal.
What does the UK want to change?
The Government suggested red and green lanes for goods imported from Great Britain to Northern Ireland.
Trusted traders who are sending goods to Northern Ireland only would use a green lane, meaning they would be exempt from customs checks.
A red lane would be used for products going to Ireland and the rest of the EU. These would be subject to full checks.
The EU triggered legal action last year over the UK's desire to abandon the protocol - but has agreed to examine the rules to see if they can work better.
What does Boris Johnson want?
As Prime Minister, Mr Johnson drew up legislation that would give ministers the power to unilaterally scrap parts of the Protocol - part of the deal that he had signed.
The shamed ex-PM is determined to protect what he sees as his legacy on Brexit - and has already been sniping from the sidelines.
At the weekend, a source close to Mr Johnson said it would be a "great mistake" to abandon his law-breaking bill even if he gets an agreement with Brussels on changes.
Mr Johnson's interventions have raised eyebrows as rumours continue to swirl that he wants another shot at being Prime Minister, after he was ousted by his own MPs over Partygate and sleaze.