Britain should negotiate its own free-trade agreement with China if talks between the European Union and Beijing fail to yield one, Boris Johnson has said.

Trade talks between European and Chinese leaders which could pave the way for a free-trade deal are due to open imminently, but the mayor of London recognised there could be difficulties.

Brussels and Beijing narrowly avoided a trade war earlier this year over European tariffs on Chinese solar panels.

At a British Chamber of Commerce event in Hong Kong, Johnson asked the audience what they wanted to change in London to help break down barriers between the west and the east. He was told to reform import duty and sort out VAT claim-back issues at Heathrow airport.

Johnson said: "VAT and import duty – those it seems to me are classically things that can be resolved by growing trade and co-operation between London and China, London and Beijing. We need a proper, thoroughgoing free-trade agreement. If the EU won't do it we can do it on our own."

Johnson's remarks will give succour to Eurosceptic Tory MPs who want more UK trade independence, and they were warmly welcomed by the audience of mainly expat business people.

It is understood the mayor is not calling for unlimited migration or freedom of movement between the two nations, something he has in the past advocated with Australia and New Zealand.

Johnson said: "Free trade would bring greater prosperity in both Britain and China and we should embrace it.

"It would mean better access for British projects to Chinese markets, access that would bring huge benefits to London's economy, creating jobs and growth."

Johnson has been in China since Sunday promoting British products and courting Chinese investment in London.

Last month he called on David Cameron to deliver "serious and proper and substantive" reform of the "intrusive" EU.

The prime minister is committed to renegotiating the UK's relationship with Brussels before putting an in/out referendum on the EU before the British public.