A MISLEADING advert claiming that most local people back an airport expansion, has been banned.

The Advertising Standards Authority (ASA) has banned the advert from Back Heathrow - a lobby group set up to push for a third runway - after the group was was criticised for failing to provide polling data to back up its claim.

Back Heathrow, which is funded by Heathrow Airport, ran a regional press ad headlined "Rallying For The Runway" which included with the line "Don’t believe the hype. Most people living in communities near Heathrow Airport support its expansion".

The Advertising Standards Authority received five complaints that said the claim that the group had widespread local support was misleading.

Back Heathrow said in a footnote to the ad that the latest independent polling showed 60 per cent of local residents had “expressed an opinion in support of expansion”.

The ASA found that to get to the statement of 60 per cent in support, the Back Heathrow campaign had excluded 15 per cent of those surveyed on the grounds they had not expressed any opinion, creating their own analysis of just for and against.

A spokesperson from the ASA said: “Given that a significant number of respondents, who had expressed an opinion albeit a neutral one, had been excluded from the sample, we considered that this was not a suitable methodology by which to draw such a conclusion.

“We considered that the evidence held back by Back Heathrow demonstrated that only 50% of all those polled were in support of expansion.”

The ASA said therefore Back Heathrow did not substantiate its claim that “most” people living in communities near Heathrow airports supported its expansion.

The ASA spokesperson added: “Consequently, the ad breached the [advertising] code.

“We told Back Heathrow not to repeat the claims, unless it held robust substantiation for them.”

John Stewart, chair of HACAN, the campaign group which opposes Heathrow expansion, said: “This ruling is a real blow to Back Heathrow as a cornerstone of its strategy has been to try to convince decision-makers that a majority of local people back a third runway. These claims are now starting to unravel.”