EU leaders back membership plan for a post-Brexit united Ireland

European leaders have pledged to seamlessly readmit Northern Ireland into EU in the event of a vote for Irish reunification some time after Britain leaves the bloc.

The promise would allow the region to follow the example of German reunification in line with the terms of the Good Friday Agreement, which ended decades of sectarian violence in Northern Ireland.

The pact allows a referendum on reunited Ireland where there is reason to believe a majority in the province is in favour. Brexit was not foreseen when the agreement was reached in 1998.

Enda Kenny, Ireland’s prime minister, had sought the commitment from EU leaders as they signed off on guidelines for the Brexit negotiation with the UK that say the achievements of the Northern Irish peace process “will remain of paramount importance” in the talks.

Donald Tusk, president of the European Council, has said the protection of the agreement and the avoidance of a hard border between the Irish Republic and Northern Ireland will be one of the top priorities in the Brexit negotiation.

Mr Kenny, who is expected within weeks to step down after six years in office, said the EU declaration was “hugely important” but he stressed that it did not bring a vote on Irish unity any closer. “Let me be clear, this is not about triggering any mechanism,” Mr Kenny told reporters in Brussels.

“I have been very consistent in my view that the conditions for a referendum do not currently exist.”

The declaration that the “entire territory” of Northern Ireland would immediately become part of the EU if there was a vote for Irish unity was required to dispel any doubt or uncertainty, Mr Kenny said.

“The only new thing here is Brexit and it is important to provide reassurance that it does not undermine any provision of the Good Friday Agreement and that if the provision on unity by peaceful means and by consent and democratic means is invoked at some time in the future EU membership is assured and it is now unanimously accepted by the European Council to endorse that legal base.”

The declaration by EU leaders will be embraced in the formal minutes of the summit on Saturday at which they took only moments to give their blessing to a tough set of guidelines for the talks with Britain. This is seen as a clarification of international law, rather than something to be negotiated in the Brexit talks.

Mr Kenny said London, which is co-guarantor with Dublin of the 1998 deal, had taken the same view on the question of Northern Ireland’s automatic entry into the EU if the region ever joined the Irish Republic.

He noted that David Davis, the UK’s Brexit secretary, had acknowledged that Northern Ireland would rejoin the EU in the event of a vote for Irish unity.

Mr Davis told a Northern Irish MP in March that the UK government will honour its commitment in the Good Friday pact to enable the reunification of Ireland if a majority in the region voted for it.

“In that event, Northern Ireland would be in a position of becoming part of an existing EU member state, rather than seeking to join the EU as a new independent state,” Mr Davis said in a letter to Mark Durkan of the centrist nationalist SDLP.

“It would of course be for the EU Commission to respond to any specific questions about the procedural requirements for that to happen,” Mr Davis added.