Herman Van Rompuy, the former president of the European Council, has been called upon by Theresa May as a potential "influencer" to break the Brexit deadlock, sources have told Sky News.

Mr Van Rompuy, who was European Council president between 2009 and 2014, was spotted arriving at the British ambassador's residence just after 7pm.

Mr Van Rompuy was at the helm in the European Council throughout the Greek financial crisis, which threatened the stability of the euro. Greece was finally bailed out in a compromise deal overseen by Mr Van Rompuy.