Exclusive: Economists find Brexit caused 12% depression in UK exports, most of which is due to leaving single market Exclusive: Economists find Brexit caused 12% depression in UK exports, most of which is due to leaving single market Brexit has depressed UK exports to the EU by 12%, and rejoining the customs union would undo only a fraction of the damage, research shared with the Guardian shows. With the UK’s future relationship with the bloc likely to feature prominently in a potential Labour