U.K. exports surged in April to their highest level in almost three years as Britain shipped more to countries both inside and outside the European Union. The 9.1 percent increase—the biggest monthly rise since 2003—left the trade deficit little changed at 10.5 billion pounds ($15.2 billion), figures from the Office for National Statistics published Thursday show. Imports jumped 5.9 percent. The total deficit, which includes a 7.2 billion-pound surplus on trade in services, narrowed marginally to 3.3 billion pounds. The figures provide the last snapshot of trade before Britain holds its referendum on European Union membership. A record deficit in the first quarter fueled concern about the sustainability of the economy and supporters of staying in the EU say things will get worse if voters opt for Brexit on June 23. The jump in exports in April was led by chemicals, machinery and oil, the ONS said. Export volumes rose 11.2 percent, the biggest rise since records began in 1998. Imports stood at their highest level since the end of 2014 and were driven in the latest month by chemicals, machinery and ships. EU Debate Sales to the EU—the destination for almost of half of British exports—rose 7.7 percent on the month. Shipments to non-EU nations surged 10.2 percent. The ONS said revisions suggest trade acted as less of a drag on the economy than originally estimated in the first quarter. The figures provide grist for both sides in the increasingly heated referendum debate. The trade deficit with Europe widened in the latest three months, boosting Brexit supporters who say other EU will countries would be keen to offer favorable terms to Britain. By contrast, the deficit with non-EU countries narrowed by more than 2 billion pounds in the period. The EU nevertheless remain the biggest market for British exporters, which sell three times more to its member states than they do to the U.S.