The conservative Northern Irish party’s 10 MPs are likely the only option the Conservatives and Theresa May have to govern effectively, as they fall just short of a majority in the House of Commons.
The party, the largest in the devolved Northern Irish Assembly, backed Brexit and has consistently blocked attempts to introduce gay marriage or more liberal abortion laws to the province. Now, the Democratic Unionist Party will have a large part to play in UK politics after the hung parliament result in the general election.
In Northern Ireland, the party defines itself by its unionist stance - its support of remaining part of the UK.
The party won two extra seats in what leader Arlene Foster called “a good night for the union”.
Its republican rivals Sinn Fein - who govern the province with the DUP - won seven seats but its MPs abstain from taking their seats. They reaffirmed this position on election night.
It is unlikely the DUP would enter any kind of deal with Labour. Foster has previously said Jeremy Corbyn is “beyond the political pale” for his sympathy with the IRA at the height of the Troubles.
When Foster was eight, she witnessed an IRA attack on her father, a policeman, outside the family home. He was shot and crawled into the family home covered in blood but survived.
The DUP’s manifesto also backs Trident, which would further put them at odds with Labour.
Foster has said Theresa May is “well within political mainstream”.
The prime minister has made overtures to the DUP before. Both Foster and her deputy Nigel Dodds were invited to the Tory Party conference last year.
They met the prime minister in October and afterwards Foster praised her “characteristically practical and responsible manner”.
May’s Christian faith could make her a more palatable ally to the socially conservative party.
Though the DUP backed Brexit, Northern Ireland voted to remain and leaving the EU raises the prospect of a damaging new border with the Republic of Ireland - the UK’s only land border.
The DUP is already preparing to tell the Tories it will only prop them up if they agree to only pursue a soft Brexit and remain in the Single Market, according to reports, scuppering Labour’s plans for a minority government
DUP MP Jeffrey Donaldson said the party would be a in a “very, very strong negotiating position” if the Tories asked for their help.
“This is perfect territory for the DUP obviously because if the Conservatives are just short of an overall majority, it puts us in a very, very strong negotiating position and it is one we would take up with relish,” he told the BBC.
“We will be serious players if there is a hung parliament. We will talk to whoever is the largest party, it looks like the Conservatives.
“We have a lot in common, we want to see Brexit work, we want to see the Union strengthened. I think there is a lot of common ground.”
As the results came in on election night, Foster said: “We are very pleased with the way in which people have reacted to the positive message of the campaign.
“It was about the Union, the importance of the Union, and unionists have really come out in their numbers.
“We fought this election on the importance of the Union and I think people really responded to that.”
Northern Ireland’s assembly and executive are both suspended and the DUP and Sinn Fein are negotiating on their restoration.
They were both suspended in January when Sinn Fein’s Martin McGuinness resigned as deputy first minister, which automatically triggered the downfall of the province’s power-sharing government.