LONDON (Reuters) - The European Union and Britain will have to engage in accelerated Brexit talks over the summer if they are to reach a deal and prevent trade links from being shattered, an adviser to the EU's chief trade negotiator Michel Barnier said on Friday.
Stefaan de Rynck said he did not expect a breakthrough at the talks next week.
"I'm not so optimistic about Round 4, hopefully we make some progress, it won't be a breakthrough," he told an Institute For Government event. "We will have to negotiate over the summer. It will have to happen at an accelerated pace."
The United Kingdom left the EU on Jan. 31 but the main terms of its membership remain in place during a transition period until the end of this year, allowing it time to negotiate a new free trade deal with the bloc.
Both sides have said they remain far apart on many issues and they traded barbs earlier this month over the talks.
De Rynck said while Britain had always taken a combative approach, relations had remained cordial and the Europeans were perplexed by a letter from the British negotiator that accused the EU of offering a "relatively low quality" trade agreement.
Britain has said the bloc needs to break the impasse and de Rynck said any agreement needed to be struck soon to avoid the disruption that would come with a no-deal departure, or a late agreement.
"You look at a situation where we agree the future in September, October, November but with very little time to prepare," he said. "And in which case I would still expect quite a bit of disruption on the first of January."
He added the EU remained open to an extension and both sides should work at all costs to avoid a disorderly exit.
(Reporting by Kate Holton; editing by Costas Pitas)