Chief executives of some of the UK’s largest businesses have backed the UK to remain in the European Union.
Leaders – including those from Heathrow, Gatwick and Easyjet – signed a letter published in The Timeswhich said an EU exit could threaten jobs, investment and growth.
The letter says: "Business needs unrestricted access to the European market of 500 million people in order to continue to grow, invest and create jobs.
"We believe that leaving the EU would deter investment and threaten jobs. It would put the economy at risk."
Speaking about the EU’s impact on trade, aviation and British prosperity, Heathrow CEO John Holland-Kaye (pictured) said:
“Heathrow believes that the UK will be better off remaining in a reformed EU. We are the UK’s only hub airport, connecting Britain to over 80 long haul destinations, and handling over a quarter of UK exports – but we recognise that for business to thrive we also need to be part of the single European market.”
He added that membership of the EU has made air travel “affordable and convenient”.
“A vote to remain offers the best of both worlds – it secures our place as a powerhouse in the global economy, while remaining in the world’s largest free trade zone.”
Downing Street said the letter was “unprecedented” with prime minister David Cameron pledging to travel to all parts of the UK to make his pro-EU case.
A referendum on whether the UK should stay in the EU will be held on 23 June.