David Cameron said it was in Britain's fundamental interest to remain very close to the European Union when it renegotiates a new relationship with the bloc it voted to leave in a referendum last month.

Speaking to global aerospace executives at the Farnborough airshow, Cameron said Britain must accept the reality of the vote and must make it work, including forging a new relationship with its European partners.

"The big strategic decisions are for the next prime minister but the groundwork is underway," he said on Monday.

"All I would say about the outcome is this: I believe it is in our fundamental national and economic interest to remain very close to the European Union, for trade, for business, for security, for cooperation. So let that be our goal."