The agricultural sector is small, with potatoes being the only major export commodity. Although Malta is an island, the fishing industry is also relatively insignificant. With few natural resources, governments have sought to develop the economy through tourism and export-dedicated manufacturing. Tourism now accounts for over a quarter of Malta’s foreign exchange earnings. The industrial sector includes textiles, footwear and clothing (the most important of the new industries), plastics, printing, electronic components and electrical equipment. The old naval dockyards used by the British have now converted to operate as a commercial shipyard. Malta has developed close economic links with Libya, which has invested heavily in property and commerce on the island as well as supplying the bulk of the oil that meets the island’s energy needs. France has become the principal market for exports, followed by the USA, Germany, Singapore, the UK and Italy. The main economic policy issue under debate in Malta is relations with the EU and the country’s application for membership. The conservative Nationalist Party (PN) favors joining while the Maltese Labor Party is strongly opposed to membership. After a sudden withdrawal in 1996 of its original application, the PN administration reapplied in 1998. The PN went on to win the 2003 poll, and Malta's membership was endorsed in March 2003 by popular referendum. Negotiations progressed fairly smoothly and Malta joined the EU, along with nine other countries (mostly from eastern Europe), in May 2004.