DUNDALK, Ireland, April 30, 2018 (Reuters) - Britain and European Union negotiators must make rapid progress on the issue of the Irish border by a June EU leaders meeting that will be a "stepping stone" towards attempting to reach a final deal in October, the EU's Brexit negotiator said. Northern Ireland will be the UK's only land frontier with the EU after its leaves the bloc. Both sides say they are committed to keeping the border with Ireland open, but finding a practical solution has proved elusive so far. The EU and Dublin insist the Brexit treaty must lock in a backstop arrangement in case a future trade pact does not remove the need for controls. London signed up for this last month but disagrees with the EU's means of achieving it.. "As far as progress and June are concerned, June is in my view a stepping stone for the October European Council, which will be the final council for reaching an agreement on the withdrawal," Michel Barnier told a news conference in the Irish border town of Dundalk. "On Ireland and Northern Ireland, let me be clear once again: only Northern Ireland specific solutions will work. We need to ... agree rapidly by June on the scope of all island customs and regulations - the safety and controls that we need to respect the single market. I don't want to go into details." Under the EU proposal, if all other attempts to avoid a hard border fail, Northern Ireland would form a "common regulatory area" with Ireland and 26 other EU states, in effect keeping the British province in a customs union with the EU. Britain, which is still debating its own Brexit strategy, says an EU-UK free-trade deal to be sealed by 2021 can solve the border issue, and Prime Minister Theresa May has rejected the EU proposal as a threat to the constitutional integrity of the UK.
