The departure lounge at Gatwick’s south terminal

The Advertising Standards Authority upheld two particular complaints around claims over additional people affected by noise at Heathrow if a new runway was built.

The ASA said that the advert’s claims were unclear.

According to Gatwick  “320,000 additional people” would be affected by a new runway at Heathrow versus 18,000 at Gatwick.

The ASA pointed out that this didn’t include estimates for people removed via improvements in technology and changes to flight paths.

This reduced the numbers to 15,500 for Gatwick and 56,500 for Heathrow.

“The ads did not make clear that the quoted figures related to the number of people who potentially would be affected in 2050, in comparison with those who potentially would be affected if expansion did not go ahead, plus they did not refer to the number of people who would be “newly removed” as a result of expansion,” the ASA said.

A spokesperson for Gatwick told the BBC: “Gatwick Airport makes no excuses for making the public aware of the huge difference in the number of people who would be impacted by noise if Heathrow were to expand, compared to Gatwick, and the figures were not disputed.

“While we disagree with the ASA’s assessment of how these figures were presented, the advert in question will not be used again.”

Last month the long-awaited report by the Airports Commission recommended that a new runway be built at Heathrow. However, the government will have the final say on any decision.