British airways chief executive Willie Walsh is seeking to soften Conservative opposition to a proposed third runway at Heathrow by launching a series of roadshows to drum up regional support.

The controversial plan for a £9bn expansion of the airport, which is currently operating at full capacity with 67 million passengers per annum, finally gained government approval in January.

Walsh is attempting to win over any future Conservative administration to the idea by using a two-pronged approach. When speaking to business leaders in Newcastle yesterday, he tried to appeal to leader David Cameron’s professed interest in green issues.

As a result, Walsh claimed that blocking expansion would fail to cut carbon emissions as they would simply be transferred to other rival airports in Europe, which would take over Heathrow’s role as a transfer hub. This meant that the notion of the UK playing a leading role on reducing emissions was “nonsense”, he added.

Walsh also pointed out the importance of the airport to regional UK economies by acting as just such a hub for connecting incoming short-haul passengers to long-haul flights.

London-based politicians and journalists were unaware of how important the transfer market was to the airport because they did not need to use it to make connecting flights, he added.

“We shouldn’t take Heathrow for granted. If that transfer market were taken away, many of Heathrow’s long-haul routes would become financially unviable and disappear,” Walsh said.

His speech was the first of a planned series of events staged by Future Heathrow, a coalition of businesses, trade unions and aviation-related organisations, which includes Heathrow’s operator BAA. Other events are planned in future for business audiences elsewhere in the North, Scotland and Belfast.

Both shadow transport secretary Theresa Villiers and conservative mayor of London Boris Johnson are vocally opposed to plans for a third runway at Heathrow.