Heathrow has been likened to a “Second World War” era airport by the boss of Emirates, who warned urgent investment was required to catch up with rivals.

Sir Tim Clark said Britain’s biggest airport, which opened in 1946, was showing its age and said Terminal 3, from which Emirates flies, “looks like a utilitarian structure, post-Second World War”.

“They’re asking can I give myself a dividend, what about my bonus? Well, have a look at what’s happening in that terminal,” he added.

The Emirates president also warned Heathrow paled in comparison with aviation hubs in Asia and the Middle East, including his own company’s base in Dubai, which has taken Heathrow’s crown as the world’s busiest international airport.

Sir Tim said: “Heathrow is seriously lagging behind in many of its customer-facing functions.

“It’s an old airport and, all around, new airports are built employing the latest technologies to streamline their processes, whether it be security, check in, immigration or whatever, and making the whole thing a lot easier.”

Dubai Airport, which was opened in 1960, overtook Heathrow as the world’s busiest airport for international traffic a decade ago.

The comments come ahead of a potential change of ownership at the airport.

Spain’s Ferrovial has struck a deal to sell its 25pc stake in Heathrow to Saudi Arabia’s Public Investment Fund (PIF) and private equity group Ardian. The deal is contingent on Ferrovial and PIF finding buyers for another 35pc stake in the airport, with concerns that this structure could collapse the deal.

Speaking at the International Air Transport Association’s (IATA’s) annual meeting in Dubai, Sir Tim said any new owner of Heathrow must be prepared to invest.

He said: “The investment that needs to go into Heathrow must move at pace. You’ve got to invest, you’ve got to keep up with all the others.

“I’m hoping that the new owners will get that. But airports worldwide are not famous for spending money.”

Also speaking to the Telegraph at IATA’s meeting, Shai Weiss, chief executive at Virgin Atlantic, added that the possible change in ownership and a change in government “creates a perfect environment to consider how to improve an airport that’s the most expensive in the world”.

Heathrow’s investment plans are regulated by the Civil Aviation Authority (CAA).

The airport had sought approval to charge higher landing fees to airlines that use it, arguing the money was needed to fund investment. Airlines have successfully pushed back against such demands, leading to lower charges than Heathrow had sought.