How much longer will the United Kingdom remain "united"?

Sinn Féin is calling for a referendum on the reunification of Ireland and Northern Ireland, following its shock success at the Northern Irish election over the weekend.

It's won the most seats of any party in the Northern Irish Assembly, a first for a nationalist party.

UK correspondent Gavin Grey told Kate Hawkesby that while the UK government is ruling out a vote for now, there's now mounting pressure for change.

“Make no mistake. With the Scottish National Party winning seats in Scotland, it’s Scotland and Northern Ireland that is threatening to break away from the United Kingdom.”

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