Northern Ireland announced an end to three years of political deadlock on Friday, as the main Irish nationalist and pro-British parties agreed to a power-sharing deal. The deal came after both sides blamed each other for the standstill, which threatened an integral part of the country's 1998 peace agreement.

"We now have a basis for power sharing and we're up for that," said Mary Lou McDonald (pictured right), leader of Sinn Fein, the largest Irish nationalist party. "There is absolutely no doubt that there are serious challenges ahead but the most significant challenge will be ensuring we have genuine power-sharing, based on equality."

Previously, Sinn Fein had refused to govern with the pro-UK Democratic Unionist Party (DUP), accusing the DUP of not treating them as equals. They have also accused the DUP of routinely blocking legislation.

The DUP was also cautiously optimistic abut the deal.

"On balance we believe there is a basis upon which the assembly and executive can be re-established in a fair and balanced way," said DUP leader Arlene Foster (pictured left).

During the last three years' stalemate, London has had to take a more direct role in governing Northern Ireland than it had done since the 1998 Good Friday Agreement and establishment of the parliament at Stormont. Prime Minister Boris Johnson welcomed the agreement as a "great step forwards" for "restoring public confidence in stable devolved Government."

Irish border roadblock

One of the major sticking points between the two parties has been the future border with the Republic of Ireland after Brexit, as Sinn Fein seeks closer ties to the European Union while the DUP has spent the last two years propping up a British Conservative government that was pushing for a swift Brexit. The second iteration of a Brexit deal conceived by Boris Johnson, however, has come in for sharp criticism from the DUP because of changes which the DUP sees as imposing something akin to a border between the Northern Ireland and the rest of the UK.

Successive UK elections since the 2016 referendum have also seen the DUP and Sinn Fein — usually the two largest parties in the country — slip in popularity.

After December's 2019 election, for the first time ever, nationalist and often predominantly Catholic parties won more seats at Westminster than unionist, largely Protestant ones. However, that won't be reflected in London, because Sinn Fein candidates always stand on a pledge to boycott the House of Commons if elected, only recognizing the legitimacy of Northern Ireland's assembly in Stormont.

From the late 1960s to 1990s, the conflict based in Northern Ireland known as the Troubles killed thousands of people and injured tens of thousands more. One of the major victories for the country's Catholic minority was an open border with the south.

es/msh (AP, Reuters)