A vote by the UK to quit Europe could have a “material adverse effect” on easyJet, the budget airline has warned.

The FTSE 100 carrier, which flies more than 65 million passengers a year largely across Europe, made the warning in a prospectus for a debt issue.

Chief executive. Dame Carolyn McCall (pictured), has previously said that a Brexit “wouldn’t be good for Britain” but this is the first time the carrier has mentioned the effect it would have on its business.

As part of the EU, British airlines have access to free-movement treaties.

The carrier warned in the prospectus: “The outcome of this decision [the EU vote] could have a material adverse effect on easyJet’s financial condition and results of operations.”

However, easyJet said even if Britain were to leave, “there is a precedent for other countries outside the EU, such as Norway, being able to take advantage of these [free movement] agreements,” the Sunday Times reported.