British newspapers on Friday tout the election results. (Daniel Sorabji/AFP/Getty Images)

After last week’s shocking results, Britain’s Conservative Party had to make a deal with Northern Ireland’s Democratic Unionist Party (DUP) to return to government. It appears likely that the DUP will not go into a coalition with the Conservatives, but will simply support the “minority government” from the outside on key votes, while not being part of the coalition.

Here’s what you need to know about the DUP and the likely deal they will strike.

It is Northern Ireland’s hard-line Unionist party.

The DUP, as the name suggests, is a party that supports the union between Great Britain and Northern Ireland, and opposes nationalists and republicans who would prefer a united Ireland. In Northern Ireland’s political system, there is a very strong link between voting and religion: Most Catholics vote for nationalist or republicans; most Protestants vote for unionists. Since a peace agreement was reached a decade ago, Ulster politics have become more polarized, with Protestants tending to vote for more extreme unionists and Catholics voting for republicans, who were associated with the Irish Republican Army, instead of nationalists. This polarization benefited both the DUP, which took seats in Parliament from the less fervent Ulster Unionist Party in Thursday’s election, and the republican Sinn Fein party, which wiped out the nationalist SDLP.

It is associated with anti-Catholic evangelical Protestantism.

Originally, the DUP was closely associated with the Free Presbyterian Church of Ulster, which was founded by the Rev. Ian Paisley, who also led the DUP for decades. The Free Presbyterians are evangelical, fundamentalist Christians. In contrast to conservative evangelicals in the United States, who forged a tacit political alliance with conservative Catholics decades ago, the Free Presbyterians have strong anti-Catholic views. Paisley himself was involved with anti-Catholic paramilitaries in the 1960s and notoriously yelled that Pope John Paul II was the “Antichrist” when the pontiff visited the European Parliament in the 1980s. The relationship between the church and party has weakened over time: Paisley’s successor as party leader, Peter Robinson, started the movement away from domination by the Free Presbyterians, and the current DUP leader, Arlene Foster, is a member of the Episcopalian-linked Church of Ireland. Nonetheless, the party’s association with a particular brand of fundamentalist Christianity has shaped many of its political positions (including not only hostility to Catholic Irish nationalism, but to homosexuality too).

The DUP is finding its feet again

After Paisley’s departure as party leader, the DUP had some difficult times. Robinson had been Paisley’s right-hand man for decades, but struggled to fill the shoes of his more charismatic predecessor, especially after becoming embroiled in a financial scandal involving his wife Iris Robinson’s 19-year-old lover. Robinson’s successor, Foster, faced her own less salacious scandal involving a government incentive scheme that ended up costing vastly more than expected, leading to instability in Northern Ireland’s governing executive. However, the DUP did very well in Thursday’s election, not only nearly eliminating the rival Ulster Unionist Party, but also doing so by apparently attracting a surge of new voters. A cooperative relationship with the Conservative Party is likely to strengthen the DUP’s position.

The DUP opposes abortion and gay marriage

European conservatives, unlike US conservatives, have mostly accepted abortion and gay rights. The DUP’s neighbors in the Republic of Ireland have a conservative government – but one which is now led by an openly gay man, who is contemplating a limited relaxation of Ireland’s constitutional near-ban on abortion. Scotland’s Conservative party is led by a gay Protestant woman who is about to marry her Irish Catholic partner.

The DUP stands outside this European mainstream. In the 1970s, it notoriously led a ‘Save Ulster from Sodomy’ campaign, and DUP members still regularly make homophobic comments. Iris Robinson, for example, has described homosexuality as “disgusting, loathsome, nauseating, wicked and vile.” Northern Ireland, unlike the rest of the United Kingdom, has an effective ban on abortion, which has been maintained in large part thanks to DUP support.

The DUP will surely use its bargaining position to keep same-sex marriage and abortion out of Northern Ireland. It is unlikely that it will be able to extend its social values to the rest of the UK, given opposition from Scottish Conservatives, and the more general tacit belief of UK mainland Conservatives that nineteenth century morality is not a vote-winner. The DUP is also likely to press for money. Northern Ireland’s economy depends heavily on public spending that is subsidized by the United Kingdom as a whole, and the DUP will be pressing for more of it, which they can then take credit for with voters.

DUP support might have implications for Brexit.

Northern Ireland has been put in a particularly tricky position by Britain’s decision to leave the European Union. Northern Ireland’s economy is linked both to the British economy and to that of the Republic of Ireland, which will remain a European Union member. Therefore, economic relationships would become far more complex if there were a “hard border” set between Northern Ireland and the Republic.

This situation could also have implications for the peace deal in the North, which was facilitated by the fact that both the United Kingdom and Ireland are member nations of the EU. The DUP is pulled in both directions on the EU – in practice it wants a ‘soft Brexit,’ which would involve an amicable deal between the EU and UK on issues such as customs, but in principle it has been quite hostile to the EU as a political entity.

The practical reason it wants the UK to make a deal on Brexit is because it wants to undercut Sinn Fein and Northern republicans. Sinn Fein wants a border deal where Northern Ireland would have special status, with unique arrangements for the border between Northern Ireland and the Republic of Ireland. This would lessen the impact of Brexit and possibly dissociate Northern Ireland from the United Kingdom, pushing a little further towards an eventual united Republic of Ireland. For Sinn Fein, the best outcome is one that clearly separates Northern Ireland from the UK, providing a wedge that can be used to separate Northern Ireland from the United Kingdom and push it towards the Republic.

The DUP, in contrast, has demanded that there be no special status for Northern Ireland as part of its deal. It wants the border question to be resolved, both because of the economic interests of DUP voters who would be hurt by a closed border, and because questions over the border can be exploited by Sinn Fein. This means that it wants Brexit to involve a deal on customs and immigration that would not have a special carveout for Northern Ireland, but instead involve a blanket arrangement for all of the United Kingdom.

However, if the DUP’s head says that a soft Brexit deal is a good idea, its heart is anti-EU. The DUP’s leader, Ian Paisley believed that the EU was (as described in a paper on his website) a secret Catholic plot to dominate Europe. During the Brexit campaign, the DUP received a somewhat mysterious large donation, which it used to fund a newspaper supplement in the mainland UK arguing for Brexit. While it is probable that the DUP will work towards a soft Brexit as it has claimed in public, strengthening the hand of those Conservatives who want a mutually agreeable accommodation with the E.U, there are close informal connections between the DUP and hardline pro-Brexiters, which will likely lead to continued speculation about what’s actually going on.

[An earlier version of this post was published on June 9, 2017].