Irish Prime Minister Enda Kenny has caused controversy after suggesting that Northern Ireland could hold a referendum on uniting with the Republic.

Mr Kenny said that supporters of the European Union in the North could demand the move in a bid to stay in the EU once the United Kingdom has left.

“The discussions and negotiations that take place over the next period should take into account the possibility, however far out it might be, that the clause in the Good Friday Agreement might be triggered,” the Taoiseach said.

“In the same way as East Germany was dealt with when the wall came down, and was able to be absorbed into West Germany and not have to go through a tortuous and long process of applying for membership of the European Union.

“Because if that possibility were to happen you would have Northern Ireland wishing to leave the United Kingdom, not being a member of the European Union and joining the Republic, which will be a member of the EU.”

The Times reports that the Good Friday Agreement, which was part of the peace process in Northern Ireland, states that a vote to unite with the Republic of Ireland can only be called in the event of a clear shift in public opinion.

A poll taken in 2012 suggested that just seven per cent wanted to leave the UK and join the Republic, however Northern Ireland voted by 56 per cent to 44 to remain in the EU in last month’s referendum.

As part of Project Fear, the Remain campaign had raised the prospect of the border controls between the Republic and the North if Britain were leave the EU.

In a joint appearance, former Prime Ministers John Major and Tony Blair said a Brexit vote could undermine the peace process, adding the “unity of the UK itself is on the ballot paper”.

Mr Kenny’s comments have been condemned by Unionists, however.

Democratic Unionist MP Ian Paisley Jr said: “It’s quite pathetic — one would have expected better from him. [He] is being deliberately mischievous… There’s not going to be a border poll, that’s the bottom line.”