THE Taoiseach today warned EU leaders of a potential return to the dark days of violence in the North if Brexit resulted in a hard border.

Leo Varadkar also cautioned that businesses in the UK will soon make decisions that “bite”.

The Fine Gael boss used the story of an IRA bombing of a customs post to emphasise to EU leaders the importance of the border issue.

At an EU summit dinner the previous evening, Varadkar brought in a copy of that day’s Irish Times which detailed an IRA blast that killed nine people in August 1972.

Four customs officials, two lorry drivers and three IRA men died in the explosion at Newry customs clearing station.

Mr Varadkar held up the paper during the meeting to stress the importance of how far Northern Ireland and Ireland have come since the Troubles, journeying from violence to peace.

Mr Varadkar described Brexit as “the political equivalent of climate change” and warned of a return to violence in Ireland if a hard border re-emerges.

He said: “That is what used to happen when we had customs posts in Ireland. I wanted to make sure there was no sense in the room that, in any way, anybody in Ireland was in any way exaggerating the real risk of a return to violence.”

The Taoiseach also predicted that businesses in the UK will soon make decisions that “bite” — and admitted that reaching a Brexit deal could take more time.

Although the EU summit was billed as the deadline for signing off a deal between the EU and the UK, Brexit negotiating teams are now looking towards the December summit and perhaps beyond to reach an agreement.

Speaking yesterday Mr Varadkar said: “I really think it’s in everyone’s interest that we get an agreement as soon as possible.

“Politicians may be able to make late, last-night decisions in rooms in the new year or in December — but businesses are going to make plans long before that.

“Businesses, banks, employers, airlines will start making decisions and they will start making decisions that bite, particularly in the UK but also in Ireland and other places.

“And I think it’s in the interests of all of our citizens that the politicians and officials get on with this and get it done as soon as possible.”