"The long and the short story is that talks are continuing in London. Significant divergences remain. Both sides are working hard to overcome them but the outcome is uncertain," Stefaan de Rynck, a member of the EU Brexit negotiating team led by Michel Barnier, told a seminar.

"This has been a marathon. We are probably past kilometre 40," de Rynck said, adding that negotiators helped themselves to pizzas during talks that lasted late into the evening on Wednesday.

(Reporting by Gabriela Baczynska; editing by Kate Abnett)