How would Northern Ireland vote on a referendum to leave the United Kingdom?
As part of the Good Friday Agreement there is a provision for a border poll to be held, though none is planned at the moment.
Sinn Fein have repeatedly called for that vote date to be announced.Right after the Scottish vote Sinn Fein leader Gerry Adams called for a border poll again.
"It is time for the people who share this island to have a respectful and informed debate with regard to Irish unity or continued partition," he said.
As this graph from Nama Winelake shows by 2016 there will be an unstoppable march towards a Catholic majority in the North based on demographic trends.
The graph is quite striking with Catholics moving from 33 per cent of the population after the partition of Ireland to 50 per cent by 2016 in less than a century.
But of course that does not mean that all Catholics would vote to leave the union.
Similar to Scotland there is a significant number of Catholics happy with the status quo, mostly in the middle class. There are very few Protestants who would vote to leave the union
But if the DUP-led government refuses to work cooperatively with the Sinn Fein party they share power with there would be a considerable pressure on Catholics of all stripes to send a strong message.
It would be a huge issue for any Catholic to vote against a united Ireland when push came to shove and a recalcitrant DUP would make it even harder for them to vote no.
The Scottish voted 45 per cent to leave the union, a remarkable number given that such an option was not on the horizon even a decade ago.
The number in Northern Ireland at present would probably be similar given the growth in the Catholic vote.
Whether that number increases or not will come down to how Sinn Fein manages the issue and how the DUP learn to share power.
Of course unlike Scotland there are massive and deep historical antagonisms at stake in the North. Some militant Loyalists have already drawn up doomsday repartition maps, ceding three counties to the independence side, Armagh, Tyrone and Fermanagh. The option of an independent Northern Ireland simply does not exists
A border poll would be fraught with difficulty not just for Northern Ireland but the Irish Republic and Britain too.Yet its day may not be far off.