UK Trade Deal: Britain, EU Clash Over Post-Brexit Ties

European Union chief Brexit negotiator Michel Barnier and British Prime Minister's Europe adviser David Frost are seen at start of the first round of post -Brexit trade deal talks between the EU and the United Kingdom, in Brussels, Belgium, on March 2, 2020. Oliver Hoslet/Pool via Reuters

LONDON/BRUSSELS—Britain and the European Union clashed on Thursday over the chances of securing a free trade agreement, with Brussels deeming it “unlikely” but London holding out hope one could be reached in September.

Since Britain left the bloc in January, talks on the trade agreement and other future ties have all but stalled, with each side accusing the other of failing to compromise before a transition period runs out at the end of this year.