One extra flight a week between an expanded Heathrow and China could generate an additional £16 million a year and hundreds of extra jobs, research by the airport claims.
The result was revealed as prime minister Theresa May departs on a trade mission to China.
The research also identifies an “urgent need” to add capacity on Chinese routes to support the government’s trade strategy.
Carried out by Frontier Economics, the study reveals Heathrow’s direct flights to China already contribute more than £510 million a year to the UK economy, creating almost 15,000 jobs.
Adding just one frequency a week to existing routes would provide a further cash injection of £16 million a year as a result of increased business travel, and stimulation for increased trade and investment between China and the UK.
This incremental increase in capacity could also support an additional 530 jobs a year.
This is a “small taste” of the opportunities that will accompany up to 40 new-long haul routes and increased frequency that a third runway at Heathrow would create, the airport claimed.
More than 100 direct flights to China are offered from the west London hub every week. Of these, 55 go to Hong Kong, 22 to Shanghai, 20 to Beijing, 10 to Guangzhou and two to Qingdao.
Of the £510 million annual contribution by existing routes, £315 million is made up by Hong Kong, followed by Beijing and Shanghai.
But rival EU hub airports with available capacity are able to fly to 14 other Chinese destinations.
Heathrow is carrying out its first public consultation on its expansion plans from this month.
Parliament is expected to vote on a National Policy Statement in the first half of the year, which will set out the policy framework for Heathrow’s final planning submission.
John Holland-Kaye, Heathrow chief executive, said: “Heathrow is proud of its role as a gateway to these vital Chinese markets; enabling global trade as the UK’s largest port by value, acting as a catalyst for thousands of jobs for the local community and contributing billions to the UK economy.
“Expansion of Heathrow is a chance to deepen relations between China and the UK; as the report highlights, just one extra route could contribute hundreds of jobs and millions to the UK’s GDP.
“As the country prepares to leave the EU and China’s economy continues to grow exponentially, this is an opportunity the UK cannot afford to miss.”