George Osborne insists the United Kingdom needs to achieve the closest possible relationship with the European Union after Brexit, if it is not to deter Chinese investors.

The former UK chancellor of the exchequer - who was a key architect of the new "golden era" of UK-China relations - said many invested in the British economy as a "jumping off point" to gain access to Europe.

"I strongly believe it is in Britain's interest, Europe's interests and, indeed, more broadly in the interests of the world economy that our relationship with Europe is as strong as it can be outside of the EU," he said.