Jeremy Corbyn has insisted he is not advocating or asking for a referendum on Irish unity.

The Labour leader said if he was to become prime minister, he would only trigger a border poll in line with the terms of the Good Friday Agreement – which stipulates a vote can only be called if there is evidence that a majority in Northern Ireland would support reunification.

Mr Corbyn, who in the past made no secret of his support for a united Ireland, was pressed on the issue yesterday during his first visit to Northern Ireland as Labour leader.

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He fielded questions from students at Queen’s University in Belfast a day after his official spokesman said Mr Corbyn believed there was majority support for unification across the island of Ireland.

A border poll, which would see separate votes north and south, can only be called if the UK Government believes a majority within Northern Ireland is in favour of unity.

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Asked by a politics student whether he would call a referendum if he became prime minister, Mr Corbyn responded: “That would be a decision that would be made within the terms of the Good Friday Agreement.

“If that is a wish then clearly such a poll would happen.

“I am not asking for it, I am not advocating it. What I am asking for is a return to the fullness of the Good Friday Agreement which would open up the opportunity and possibility for the future of Ireland as a whole.

“That is the point of the Good Friday Agreement. Not direct rule, not imposition of a political view from Westminster but devolution of powers to Stormont here [in Belfast] and of course the relationship with the Republic.

“It’s quite clear that it’s there for a poll on both sides of the border should that be demanded.”

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Earlier, Mr Corbyn warned that Northern Ireland stood at a potential crossroads between a strengthened peace or a return to the dark days of the past.

He urged Stormont leaders and the UK and Irish governments to renew efforts to restore powersharing at the crisis-hit institutions in Belfast, insisting peace cannot be taken for granted.

Mr Corbyn, on a two-day visit, also used his speech at Queen’s to make clear that Labour will not support a Brexit deal which results in a hard border.