'˜I cannot foresee NI violence due to Brexit' says ex-taoiseach

Mr Ahern suggested that he does not feel violence arising from the UK’s decision to leave the EU is a likely prospect, although it may cause “tensions” within the Sinn Fein/DUP-led Executive.

However, fellow former Irish leader John Bruton cited the recent murder of Adrian Ismay as a reason to be “very careful” around the Northern Irish preace process.

Prior to the referendum, two ex-UK Prime Ministers – Tony Blair and John Major – were widely quoted in the media as having warned that Brexit could undermine the peace process.

On June 9, The Financial Times quoted Mr Blair as saying that it would be “profoundly foolish to risk [the] foundations of stability” which the peace process had brought about by quitting the EU.

Speaking at a House of Lords Committee on Tuesday, Mr Ahern said: “All of these uncertainties... I’m not suggesting they lead to disorder or community troubles or anything like that, I just do not see that,” Mr Ahern said.

“But it does lead to tensions within the Executive, the Assembly, north and south.”

Mr Ahern added: “Nobody is happy. I don’t know anybody really that is happy that the United Kingdom is pulling out of Europe. I can’t think of one person.

“I think it’s the uncertainty with the issues. I really can’t see any violence or related problems.”

Also speaking at the House of Lords’ EU Select Committee, fellow ex-taoiseach John Bruton said it should not be forgotten that prison officer Adrian Ismay died after dissident republicans targeted him in a car bomb attack in Belfast in March this year.

“We shouldn’t forget that that has happened, even this year. So we have to be very, very careful,” he said.

Mr Bruton also said questions remained over whether disadvantaged communities in Northern Ireland could suffer from a fall in funding agreed with Europe under the peace process.

The committee was told there is confidence the common travel area between Ireland and Britain will survive Brexit.

But Mr Ahern said he had huge concerns about a border being created which would hit the free movement of people.

“I really think that us opening up a border, if we have customs and tariffs, bad enough, but if we start building it around people in any form you can see the difficulties and that would be a huge concern I’d have in what is a good peace process but how you could start undermining that,” he said.

“You don’t have to go too far back to know how customs posts were used in the 50s and 60s as targets.”