The Netherlands earned €20.5bn last year exporting goods and services to Britain, the equivalent of 3% of GDP, according to new figures from the national statistics office CBS.

This makes the UK the Netherlands’ second most important export market after Germany. Belgium is in third place, followed by the US and France, the CBS said.

Meanwhile, export associations said on Friday that two-thirds of companies involved in exporting to Britain do not think British voters will opt to leave the EU in next week’s vote.

And those that do, expect the effect on their businesses to be limited, the research by export association Fenedex and other organisations shows.

A British withdrawal from the EU will cost the Dutch economy €10bn in lost income by 2030, according to calculations by the government’s macro-economic think tank CPB last week. The drop in trade with Britain will mount up to 1.2% of GDP within the next 15 years, the CPB said.