Tony Blair and Sir John Major will travel to Northern Ireland on Thursday to warn that the peace process and the future of the UK could be jeopardized if Britain votes to leave the EU, the Financial Times reported.
The two former prime ministers will raise the stakes in the referendum campaign by warning that a Brexit could see the reintroduction of a “hard border” in Ireland between north and south, reigniting political tensions.
Sir John will also claim that if Britain left the EU it could trigger an “uncontrollable and irresistible” demand for a second independence referendum in Scotland.
“I say without a shadow of doubt in my mind that the wrong outcome on June 23 will affect our union,” the former Tory premier will add. “That means the unity of the United Kingdom itself is on the ballot paper.”
The joint intervention by the two former political foes is an attempt by the Remain camp to shift the EU referendum debate away from immigration, and to seize back the initiative.
Their warnings on the risk posed by Brexit to the Northern Ireland peace process may carry particular resonance since both men were key architects of the 1998 Good Friday Agreement.
Blair will say: “We understand that, although Northern Ireland is more stable and prosperous than ever, that stability is poised on carefully constructed foundations.”
He will claim that Leave campaigners are putting “ideology before practical considerations”, adding: “Don’t let them take risks with Northern Ireland’s future. Don’t let them undermine our United Kingdom.”
Sir John and Blair will reflect concerns in Dublin over the possibility that a Brexit vote would put strains on north-south relations, ending the fluid movement of goods and people across a near-invisible border.
The Remain camp argues that after a Brexit vote, the border in Ireland would become an external frontier between the EU and the UK, with the possible introduction of frontier controls and customs checks.
The UK and the Republic of Ireland operate a common travel area allowing free movement between the two countries and Theresa Villiers, the pro-Brexit Northern Ireland secretary, says that would remain in place.