The Advertising Association and London agency Adam & Eve DDB are campaigning to prevent the British government from cutting off access to international talent with tighter immigration rules post-Brexit.

A giant billboard at London's biggest airport Heathrow has the words "We're a great advert for Britain" over the images of ten senior industry figures, all of whom are foreign-born but live and work in the U.K. Below is the line: "British advertising thrives on foreign talent." Other executions will appear online and in print using space donated by media owners.

"It will be catastrophic to the long-term success of the sector if we can't access the right talent quickly and easily," says James Murphy, group CEO of Adam & Eve DDB and chairman of the Advertising Association, in a statement. "Global brands want to work with the best talent and the U.K. has it. As an industry that delivers $160 billion of GDP per year for the country, anything that knocks advertising will dent the economy."

The executives pictured on the billboard include Séverine Charbon, the French global chief talent officer at Publicis Media; Jordi Bares, a Spanish creative director at Framestore; and Sherif Guindy, the Egyptian-born U.K. head of technology at Maxus Global.

At the same time, the Advertising Association, which is pushing to defend the U.K.'s global status and fight future immigration restrictions that may be part of the country's European Union exit, has published a report in partnership with LinkedIn showing that London has a higher proportion of citizens of other countries working in advertising and marketing than rival global talent hubs like New York and Amsterdam. And that talent flow is continuing. Based on an analysis of 328,000 LinkedIn accounts, 2.47% of all London advertising talent has arrived from overseas in the last 12 months, the report says. More than one-third of that talent comes from European Union countries, while others arrive from the U.S. and Australia.