Brexit has raised tensions on island of Ireland says Bertie Ahern
Brexit has "raised tensions" on the island of Ireland and "complicated" progress towards a lasting peace, one of the authors of the Good Friday Agreement (GFA) has told MPs.
Former taoiseach Bertie Ahern said people were worried that a no-deal UK withdrawal from the EU would be the start of a "slippery slope" to a hard border, with checkpoints and troops.
He said the UK's 2016 vote to leave the EU was the reason why the Northern Irish institutions created by the GFA remain suspended after more than two years.
He told a House of Commons committee the Irish government would not give up on the controversial backstop arrangements in Theresa May's Withdrawal Agreement, as they were viewed as "the only way of ensuring with certainty that we have a soft border".
Mr Ahern, who served as taoiseach from 1997 to 2008, poured cold water on any suggestion that Dublin would accept Mrs May's proposals for the backstop to be time-limited or replaced with technological solutions.
While the technology to avoid border checkpoints may be developed "in the dim and distant future", it is not available now, he said, and checks at a distance from the border would not be seen by the Republic as compliant with the GFA.
He told the Commons Leaving the EU Committee: "There is no possibility of the Irish government or the Irish people saying the backstop could be time-limited. There is no hope of that, I'm afraid.
"I don't see the EU changing on the Withdrawal Agreement, I don't see them changing on the backstop, I don't think the Irish government are going to change on that."
Mr Ahern said continued membership of the EU for both Britain and Ireland was "taken as an absolute given" when he was negotiating the Good Friday Agreement with Tony Blair and was a "key element" on which the 1998 pact was built.
He said he felt like Rip Van Winkle waking up after 20 years asleep when he heard opponents of the backstop argue that Northern Ireland must be treated the same as other parts of the UK, when the agreement made clear that both sides accepted the constitutional position was different.
Mr Ahern said: "Most people remember the border and remember sitting in long queues.
"They fear that any infrastructure at the border equals trouble, disagreement, army, soldiers, police. Some of it might be exaggerated but there is that fear of the slippery slope. It is something that really worries people."
Brexit "has raised tensions again, it has brought back a lot of the rhetoric of the past, it's brought back a lot of the issues of the past", he said.
"It's my view that if it wasn't for Brexit, the institutions in Northern Ireland would have been up and running a year ago. Brexit has stopped that. It wasn't the reason that brought them down but it is the reason they are not back up."
Asked whether it was helpful for Taioseach Leo Varadkar to talk about sending troops to the border in the case of a no-deal Brexit, Mr Ahern replied: "Rhetoric from anybody at any time isn't helpful."
He denounced as "irresponsible" suggestions that Brexit should lead to an early poll on Irish reunification, saying this should wait until new arrangements have had time to bed in and the institutions are restored.
He told MPs: "The open and invisible border we have today is an achievement of the [peace] process and of our shared membership of the EU.
"No-one wants to see a hardening of that border and anyone familiar with life in Northern Ireland and the border counties would see the prospect of any infrastructure checks or controls... with enormous concern, and in my view they would be right."
While London, Dublin and Brussels had all voiced their determination not to erect physical infrastructure along the border in any circumstances, Mr Ahern said World Trade Organisation rules would force them to do so if the UK left without a deal.
"The Irish government say they don't want it, the British government say they don't want it, the EU say they don't want it," he said.
"I think most Irish people think, 'Well then, we will definitely have it'.
"We want to keep the relationship between Britain and Ireland in the same close and hugely positive place it has been over the last two decades. But just because we all want that doesn't mean we don't need a plan to make that happen."
Mr Ahern said a no-deal Brexit would be "devastating" for Ireland, particularly for small businesses and farms, with surveys forecasting 40,000 job losses and a 4 per cent cut in GDP.
But he said the threat of a hard border would "take precedence" over economic issues for a large majority of its people.
He said there was "almost total unanimity" in the Republic behind Mr Varadkar's insistence on the backstop, which is designed to keep the border open by keeping the UK in the EU's customs union and Northern Ireland observing certain single market rules until a wider trade deal is agreed.
"Brexit is disruptive, full stop," he said.
"Whatever way you look at it - from the UK, from the Irish point of view, from the island of Ireland point of view, north and south - it badly affects us. There's very few plus sides - I can't think of any - in UK withdrawal from Europe."