European aircraft manufacturer Airbus has sent a letter to its British employees outlining the company's fears about the prospect of the UK leaving the European Union.
Airbus bosses told staff that they "firmly believe that it makes good economic sense to stay inside the EU".
However the company stressed it was "committed" to its UK operations regardless of the referendum outcome, saying their success was built on a "highly competitive, integrated European business model".
The multi-national corporation employs 15,000 people in the UK and 132,000 globally.
This letter, which was signed by six top Airbus Group executives, including the president of Airbus Group UK, Paul Kahn, echoed a prominent Remain campaign slogan that leaving the EU would be a "leap in the dark".
"We simply don't know what 'out' looks like," the letter said.
It continued: "However, our business model is entirely based on our ability to move products, people and ideas around Europe without any restriction and we do not believe leaving will increase the competitiveness of our British-based operations.
"We all need to keep in the back of our minds that future investments depend very much on the economic environment in which the company operates."
German car mufacturer BMW has also sent a letter to its employees ahead of the vote on 23 June outlining the risks of Brexit.
