What will the DUP's demands be if there's a coalition government?
With all eyes on the DUP, what the party demand from Theresa May as the price for propping up her government? Here are some possible items on their shopping list.
The DUP will not stand for any arrangement that physically sets the region apart from anywhere else in the UK, including suggestions that border, immigration and customs controls could be set up at ports and airports like Stranraer and Liverpool rather than in Belfast or Larne.
And when it comes to the border with the Republic, Ms Foster will not want to see any physical manifestation of the divide between the EU and the UK.
Among the key priorities for the unionists will be the vexed issue of the legacy of the Troubles and the idea that army and police veterans who served in Northern Ireland should be protected from prosecution.
Another big price to pay for the party's support in Westminster could be the reinstatement of any EU subsidies that farmers lose when Brexit is a done deal. They're worth about £350m a year.
Another set of funds doled out by Brussels could also be on Ms Foster's shopping list - about £400m of payments due over the next four years that go to community development and cross-border projects as part of a dividend for the peace process.
The DUP, with its strong links to the business community in Northern Ireland, may also use its strong hand to push for a reduced corporation tax rate. The Republic's 12.5% rate has been a bone of contention at times, including with suggestions from some quarters that Dublin poached foreign investors considering locations north of the border.