Virgin Atlantic has called upon US regulators to deny the proposed joint venture between British Airways and American Airlines.

Virgin has submitted a new call to action to the US Department of Transport (DoT) against a BA-AA alliance, which would allow the carriers to merge their operations on transatlantic flights.

Sir Richard Branson, the president of Virgin Atlantic, said: “Now two competition authorities have voiced their concerns over the proposed BA-AA alliance, we renew our call on the regulators to reject these anti-competitive proposals.

“The competition authorities have thoroughly scrutinised the proposals in an effort to safeguard competition in the interests of consumers. Having done so, both the authorities on opposite sides of the Atlantic have cited concerns. These concerns are absolutely justified and the alliance should not be given the go-ahead.”

Last month, the US Department of Justice expressed its concerns about the alliance in a report, claiming it would cause “competitive harm” and could lead to fares rising by 15 per cent.

A report from the European Commission in October also backed the DoJ findings, saying that the deal could breach rules on restrictive practices.

However the DoT will have the final say on whether anti-trust immunity will be granted or denied, with a decision expected within the month.

A combined BA-AA would have a dominant position on many routes including 80 per cent of flights from London Heathrow to Boston and 62 per cent of flights from Heathrow to New York JFK.