Rising imports caused the gap to widen by £16m compared with the previous month, prompted mainly by increased purchases of works of art. Exports of goods to the EU were unchanged.

Meanwhile, the UK’s overall trade deficit - with EU and non-EU trading partners - shrunk by £0.5bn to £3.8bn in March.

Analysts had expected the economy’s trade gap to stand at a much greater £4.4bn. The unexpected drop was brought about by a 1.9pc rise in exports, compared with a lesser increase in imports of 0.6pc.

Scott Bowman, a Capital Economics analyst, said: “External demand doesn’t appear to be providing any support to the recovery and is compounding the domestic uncertainty created by the upcoming EU referendum.”