'Hard core' Brexit talks not before end of 2017: Herman Van Rompuy

Tackling the toughest issues of Britain's exit from the European Union should not happen before the end of 2017, former European Council president Herman Van Rompuy said.

The UK voted its way out of the EU in a June referendum but the official divorce proceedings cannot begin until Britain starts procedures, through triggering Article 50 of the EU's Lisbon Treaty.

Prime Minister Theresa May has said she will not begin the formal process before 2017, while Van Rompuy yesterday said negotiations on the toughest issues will have to wait until after elections in France and Germany.

"Before the German elections and before there is a new German government, no serious negotiations will take place," Van Rompuy told the BBC Radio 4 "Today" programme.

"You can always start with more technical matters but the hard core -- the difficult topics -- will be tackled after the constitution of the new German government. That will be October-November," he added.

The French election will be completed in April or May next year.

The most challenging issues on the negotiating table will likely be how Britain can achieve its aim of restricting migration from the EU, while maintaining access to the single market.

Van Rompuy, a former Belgian prime minister, said the EU would seek a deal of mutual benefit but "red lines" would stand on key areas.

"There are huge economic interests but there are also red lines. It is very well known that freedom of movement is one of those red lines," he said.

The former EU chief said that while the bloc did not feel it had to "punish" the UK, it would not want to encourage any of the remaining member states to leave.

Van Rompuy's comments came on the eve of a summit of the remaining 27 EU member states in the Slovakian capital Bratislava. The meeting is aimed at creating a roadmap for the bloc without Britain.