Global advertising leaders have reacted with disappointment to the news that the UK has voted to leave the European Union, but have insisted that London will remain a major centre for media and marketing.

The results of the ‘Brexit’ referendum was revealed this morning (24 June), showing a victory margin for the ‘Leave’ campaign of 51.9% to 48.1%. The verdict has led to the resignation of British Prime Minister David Cameron, and begins a process which is expected to see the UK leave the EU by 2018.

Leaders across the marketing and media world had warned that a ‘Brexit’ would be bad news for global advertising spend, and the UK’s place as a centre of the industry.

In a statement issued this morning, WPP chief executive Sir Martin Sorrell said he was “very disappointed” with the outcome, but acknowledged that “the electorate has spoken”.

“The resulting uncertainty, which will be considerable, will obviously slow decision-making and deter activity. This is not good news, to say the least. However, we must deploy that stiff upper lip and make the best of it,” said Sorrell.

“Four of WPP’s top 10 markets are in Western Continental Europe and we must build our presence there even further. It just underlines the importance of implementing our strategy: fast-growth markets (BRICs and Next 11), digital, data – and horizontality, which ironically means getting our people to work together, not apart!”

US-based Interpublic Group reaffirmed its commitment to its “significant presence” in the UK, despite the result of the referendum.

CEO Michael Roth added that he believes markets will “normalise” in the longer term, in spite of turbulence which has seen the UK pound drop to its lowest value against the US dollar since 1985.

“Together we’ll find footing in this new world”

“The decision will lead to market volatility in the short term, no question. But the UK is a key market to our clients and our own company, and together we’ll find footing in this new world. Longer-term, as long as open trade remains a priority, markets should normalise, and that’s the time-line we’re focused on,” said Roth.

Jerry Buhlmann, chief executive of Dentsu Aegis Network, commented that the referendum result was a “surprise”, and that the focus should be on reintroducing market stability.

“There is likely to be a short period of economic uncertainty in the UK and these economic adjustments are supported by a resilient UK financial system,” said Buhlmann.

“What is important now is we focus on building political and economic stability. This should be driven by strong leadership who are united in negotiating positive trade agreements, strengthening relationships with key international bodies and bringing the country together.

“As a global business we have a strong UK operation and whilst it is significantly important to us it only represents 6% of our global revenue. We expect our business to prosper both in the UK and globally irrespective of this result.”

And before the result had been announced, Havas global chief executive Yannick Bollore had tweeted that the UK will “remain at the forefront of our Havas European Family” whichever way the vote went.

With the majority of the global ad industry gathered this week at the Cannes Lions festival, M&M Global commissioned Mike Fletcher to find attendees in favour of ‘Brexit’ – with very little success.