The figures will be a disappointment to the government and the Bank of England, which have been hoping for an export-led recovery to lead Britain out of its second recession in four years.
However, the Eurozone debt crisis has been hurting demand in Britain's main export markets and the Bank has warned that a recent rise in sterling against the euro poses a threat to British manufacturers.
The Office for National Statistics said the June trade deficit widened to £4.3bn from £2.7bn, the largest since records began in 1997.
This was driven by a bigger-than-expected widening in the goods trade deficit, which grew to £10.12bn from £8.36bn, well above economists' forecasts of a much more modest rise to £8.63bn.
British industrial output contracted by 2.9 per cent in June, due in part to extra public holidays to mark Queen Elizabeth's 60 years on the throne, and economic output as a whole was 0.7 per cent lower – the sharpest fall since 2009 in the immediate aftermath of the financial crisis.
Goods exports were down 7.4 per cent in volume terms in June, the biggest drop since April, and fell to their lowest total value since November 2010 at £23.45bn.