Dublin: The United Kingdom leaving the European Union would be “severe” for the 28 member economic-political bloc, Emirates president Tim Clark said on Thursday, cautioning a Brexit vote could “flatline” travel demand in Europe.

Europe will vote on June 23 to stay or leave the European Union in a referendum that has become increasingly difficult to call. Campaigners, who want UK to stay with Europe, argue a leave vote would be economic suicide whilst the leave group says it would return sovereignty to Britain.

“If the Brits decide to exit the European Union, the shockwaves throughout the European Union, as it stands today, will be pretty severe in my view,” Clark, who was knighted in 2014 by the British monarchy for 'services to British prosperity and to the aviation industry', told reporters at the International Air Transport Association (IATA) annual meet in Dublin.

Emirates is the largest non-European airline flying to the United Kingdom, according to aviation think-tank CAPA - Centre for Aviation. The Dubai-based airline, the world’s biggest, will fly ten times to London by the end of the year, mostly operated by the Airbus A380. It also flies to Birmingham, Glasgow, Manchester, and Newcastle.

About 30 per cent to 40 per cent of Emirates traffic comes from Europe, Clark said.

If Britain does leave, it is expected to put further strain on the EU that is already fragmented politically over its refugee policy as millions flee turmoil in the Middle East.

There has been an increase in support for far-right nationalist parties and years of austerity have put strain on many of the EU's 28 members. 

“Brexit would just add to that,” Clark said of the uncertainty and changes in Europe.

Clark is not the first airline executive to voice concerns over the pending vote. Europe’s Lufthansa, British Airways parent International Airlines Group (IAG), Ryanair and easyjet have voiced their concerns. Australia’s Qantas has said it's in the UK's interest to stay.

“If Brexit comes along [then] we [will] see another shockwave coming through,” Clark said. “As far as we’re concerned we have to wait and see what happens,” he added, confirming the airline does have contingency plans though said he hoped traffic would “temporarily” flatline “as people think ‘how is this going to affect me?’”

On Wednesday, the chief executive of IAG subsidiary Aer Lingus said the vote “is creating uncertainty” in Europe.

“We’re an industry and a business that requires economic activity to sustain [growth],” he said, warning that British airlines might have to renegotiate its agreements allowing it to fly to Europe if the UK votes to leave.