UK exit timeline
December 2017: The EU agreed to move on to the second phase of negotiations following extensive talks on the Brexit divorce bill and citizens' rights. No solid answer is agreed on the Border, but both sides agreed an 'Irish protocol' that would effectively see Northern Ireland stay closely linked to the customs union in the event of a hard Brexit.
April 2018: The UK is continuing to work in the background on proposals for maintaining an open Border, but UK Prime Minister Theresa May's proposals reportedly underwent "a systematic and forensic annihilation" in Brussels.
June 2018: An EU summit is scheduled for June 28-29. The EU27 will decide whether enough progress has been made on the Irish question. While October is the ultimate deadline, June is increasingly viewed as the latest date for agreeing the outline of the Irish solution.
October 2018: The EU has said negotiations must be completed before October 31. This is to allow time for the European Parliament to sign off on the deal. MPs will also get to vote in the UK parliament.
March 2019: The UK is due to leave the EU at 11pm on March 29, 2019. Assuming a deal is completed, it will then enter a transition period whereby it continues to obey EU rules but is free to begin negotiating trade deals with other countries until December 2020.