Sinn Fein hailed a historic victory in the Northern Ireland Assembly election after receiving the most first-preference votes.
With all 90 Stormont seats declared, the republican party has won 27, putting it ahead of the Democratic Unionist Party (DUP) which fell by two seats to 25.
The Northern Ireland Protocol has cast a long shadow over the election campaign, following the resignation of first minister Paul Givan in February in an effort to force the UK Government to act over the post-Brexit trading arrangements. This action left the Executive unable to fully function.
While ministers remained in post, they were restricted in the actions they could take.
We break down what Sinn Fein's win means for the future of the UK.
Why is there now the prospect of a border poll on Irish reunification?
Sinn Fein, a party supporting Irish reunification, has won a majority in Northern Ireland elections for the first time.
Sinn Fein has said Brexit has accelerated the debate on reunification with EU member Ireland because most Northern Irish voters voted Remain.
Who decides whether a poll is called?
The Good Friday Agreement recognised the right of people on the island of Ireland to reunify if border polls in Ireland and Northern Ireland support it.
UK law says the Secretary of State for Northern Ireland should order a vote if it “appears likely” a majority of voters want a united Ireland but is unclear on how that should be decided. The Irish government must also agree.
But can’t Sinn Fein order a referendum?
No. In fact, Sinn Fein can’t even form a Northern Ireland Executive without the consent of the DUP. Power-sharing needs the two largest nationalist and unionist parties to agree.
This system also means the cross-community Alliance Party cannot enter into coalition with Sinn Fein, despite its strong showing, unless the DUP is also part of the administration.
Do people want reunification?
In the last referendum in 1973, 99 per cent of voters backed staying in the UK but the vote was compromised by a low turnout of just 59 per cent with many nationalists abstaining.
A poll last year found 30 per cent of Northern Irish voters backed reunification but different research found that just 50 per cent of people were in favour of remaining part of the UK.
Polls last year found that two thirds of Irish people supported reunification but more than half of them would reject that if it led to an increase in taxes. One in eight would reject reunification if it meant taking on Britain’s full costs of supporting Northern Ireland.
Will it happen?
Michelle O’Neill has tempered her Republican rhetoric to broaden her appeal and says her priority now is healthcare and the cost of living.
She will need to be a successful First Minister to build up the support she would need to eventually win a border poll.
Will a Northern Ireland Executive be formed?
That seems unlikely in the short term. The DUP has said it won't enter into power sharing agreement unless there is a deal to demand the Northern Ireland Protocol be removed or replaced.
The Brexit treaty created the Irish Sea border and many unionists fear it is driving a wedge between them and the rest of the UK.
What happens next?
Parties will meet at Stormont on Monday after results are finalised on Saturday.
The talks are not expected to end in a power sharing agreement.
That means Stormont will stagger on as a caretaker administration for at least the next five and a half weeks, rendering it powerless to implement new policies.
What about Sinn Fein in Ireland?
Left-leaning Sinn Fein also recorded a historic result in the Irish general election in 2020.
Its haul of 37 seats was just one below Fianna Fáil, who formed a coalition with Fine Gael to keep Sinn Fein from power.
If the party can build on that success in the next general election, there could be Sinn Fein leaders on both sides of the Irish border, which will surely build momentum for a border poll.
It could prove a real headache for Boris Johnson, especially with another formidable nationalist politician in Nicola Sturgeon in Scotland also pushing for a referendum on UK membership.
