The European Council -- the body representing the EU's member states -- has adopted a decision formally authorising the start of talks with the UK following the latter's notification in March of its intention to leave the EU, it said May 22.

The European Commission will negotiate on behalf of the 27 other EU member states, the council said.

The UK voted to leave the EU by the slenderest of margins, following a referendum on June 23, so the announcement ends 11 months of the phoney war, with both sides taking uncompromisingly hostile positions and UK businesses thrown into uncertainty about future trade with the bloc. 

As this is an unprecedented event, what happens next is anybody's guess; but the commission's calculation of the size of the UK's remaining financial contributions to the EU budget is likely to be at the top of the agenda and to be a lot larger than the UK's own calculation of its commitments.

The commission said it would focus first on "providing clarity for all those affected by the Brexit decision and ensuring a smooth 'separation'. That is our top priority. We are ready, we are united and we approach these negotiations with the best will and with the clear aim of reaching a deal."

Michel Barnier was named in July 2016 as the Commission's chief negotiator with the UK (Photo credit: European Council)

EU ministers have adopted a first set of negotiating directives that sets the EU position for the first phase of the negotiations. The text prioritises issues that have been identified as necessary for an orderly withdrawal of the UK, including among others citizens' rights, the financial settlement and the situation of Ireland.

A dedicated working party with a permanent chair was created to assist the Council and Coreper (Committee of Permanent Representatives) on all matters related to the UK withdrawal from the EU. This working group will always meet in an EU 27 format.

Negotiations with the UK will be conducted on the principles of transparency, it said.

William Powell