Tony Blair and John Major warn a Brexit could threaten peace process during visit to Derry
FORMER British prime ministers John Major and Tony Blair have warned that a vote to leave the EU would be a "historic mistake" which could threaten the hard-fought peace process.
But their comments have been criticised by DUP deputy leader Nigel Dodds as “irresponsible nonsense”.
The suggestion was also rejected by Theresa Villiers, pro-Brexit secretary of state, who said support for the peace process was "rock solid".
Former adversaries, Mr Blair and Mr Major shared a platform at the Ulster University's Magee campus in Derry, and warned that Brexit could lead to the break-up of Britain.
Mr Major said: "I believe it would be an historic mistake to do anything that has any risk of destabilising the complicated and multi-layered constitutional settlement that underpins stability in Northern Ireland."
Both men played crucial roles in the Northern Ireland peace process, and Mr Major warned that the "wrong outcome on June 23 could "tear apart the UK".
He added: "If we throw the pieces of the constitutional jigsaw up in to the air, no one can be certain where they might land."
Mr Blair hit out at the Leave campaign, claiming it puts an "ideological fixation" with Brexit ahead of the damage it would cause.
He said: "I say, don't take a punt on these people. Don't let them take risks with Northern Ireland's future. Don't let them undermine our United Kingdom.
"We understand that, although today Northern Ireland is more stable and more prosperous than ever, that stability is poised on carefully-constructed foundations.
"And so we are naturally concerned at the prospect of anything that could put those foundations at risk."
He also spoke of the potential damage to British-Irish relations if Britain withdrew from Europe.
"These relationships are today stronger and better than ever before," said Mr Blair.
"Of course there are differences that remain but I remember being the first prime minister to go and address the Dáil, I remember working closely with Bertie Ahern to bring about the Good Friday Agreement and then subsequently in the years following.
"We did it by working together, by coming together and realising that our common strategic interests were stronger and more important for our future than simply whatever narrow interests we might have.
"We came together as two countries, not just as politicians negotiating that agreement and we did so with the very spirit that I think is the very spirit that should inform our thinking when we come to decide this question on Europe because, for all its faults, it represents, since my father's generation, an enormous coming together of people, a belief that in working together we can advance our individual interests in a more profound and more effective way.
"And the very spirit that brought us together in making peace in Northern Ireland is the very spirit that we need to reflect upon as we come to make this decision.
"It is a sizeable decision. It is a decision of immense importance to the whole of the country and I think it is of particular importance to the people of Northern Ireland."
But pro-Brexit DUP deputy leader Nigel Dodds condemned the former prime ministers' comments as “nonsense”.
Mr Dodds called for a debate “to allow us time to debunk the nonsense being spoken today by the former prime minister Tony Blair about the peace process and the political process in Northern Ireland being under threat if we vote to leave the European Union”.
“Surely this is the most irresponsible talk that can be perpetuated in terms of Northern Ireland – very dangerous, destabilising and it should not be happening,” he added during the business statement in the Commons.
Mr Dodds told BBC Radio 4’s World At One that the two ex-premiers were engaging in “scaremongering”.
“I think it’s deeply disappointing. They know that the peace process in Northern Ireland has never been more stable. They are devaluing their own legacy,” Mr Dodds said.
Conservative Euro-sceptic Theresa Villiers said: "The vast majority of people in Northern Ireland believe their future should only ever be determined by democracy and consent and not by violence.
"I very much hope figures who played such an important role in the peace process would not suggest that a Brexit vote would weaken that resolve in any way. "Whatever the result of the referendum, Northern Ireland is not going back to the troubles of its past and to suggest otherwise would be highly irresponsible."
Ms Villiers insisted the common travel area between Britain and the Republic would continue if there was a Leave win, even though the border would become the frontier between an EU member and a non-EU nation.
"There would be risks to manage but they are not significantly more serious than risks that are already managed effectively today through bilateral co-operation between the UK and Ireland," she said.
"The idea that thousands of non-Irish EU citizens would suddenly start crossing the border is far-fetched."
Mr Blair and Mr Major had integral roles in helping to end the sectarian violence of the Troubles.
In 1993, Mr Major and Irish prime minister Albert Reynolds delivered the Downing Street Declaration which argued for self-determination on the basis of consent and paved the way for the IRA ceasefires the following year.
Mr Major told the Derry audience of teenage schoolchildren who had packed into Magee's Great Hall: "I carried this forward and Tony completed it."
Five years later, in 1998, the British and Irish governments concluded the historic Good Friday Agreement which cemented the stability and laid the foundations for the devolved power-sharing Stormont executive.
Europe also played an important part, according to Mr Blair.
"I remember the constant horror that often defined people's lives. Bringing about peace was not easy – it required a co-operative effort and involved people setting aside old enmities and positions," he said.
"It would be foolish, profoundly foolish to try to risk those foundations of stability."
Meanwhile former US president Bill Clinton, whose 1995 visit to Northern Ireland was seen as a crucial moment in the peace process, said he was worried about the potential impact of Brexit on the north.
Writing in the New Statesman magazine, Mr Clinton said: "I was honoured to support the peace process in Northern Ireland. It has benefited from the UK's membership in the European Union, and I worry that the future prosperity and peace of Northern Ireland could be jeopardised if Britain withdraws."
The former president, who worked with Mr Major and Mr Blair on the peace process, added: "Transatlantic co-operation is essential, and that co-operation is strongest when Europe is united... I hope you will stay."