Sir Howard Davies and Sir John Armitt have written to MPs ahead of a vote on the proposal

Former leaders of the Airports Commission have written to MPs urging them to vote in favour of a proposal to expand Heathrow Airport. 

Sir Howard Davies, former chair of the Airports Commission, and Sir John Armitt, who was a commissioner of the same group, have laid out the reasons the commission was in favour of a third airport at the country’s busiest airport.

Given many MPs have raised concerns that an expansion at Heathrow is continuing the trend of a focus on infrastructure in the South East, the letter laid out the reasons for needing to increase airport capacity around London.

The letter, which was sent to all MPs this morning, said: “Our analysis indicated clearly, however, that outside of the South East the challenge is not one of airport or runway capacity.

“We therefore made a number of recommendations in our interim report relating to access to and the efficiency of the UK’s regional airports, but focused our work on expanding capacity on the congested airports around London.”

The letter said while there were a number of airports in this area, they were not “interchangeable”, with an expansion of Heathrow clearly hte best option.

Davies and Armitt said none of Stansted, Luton and Southend “would provide the weight of demand which would support a more extensive long-haul network” despite having capacity for further growth. They also said City Airport had little ability to expand.

The pair said while “Gatwick would provide a more promising location for expansion” there were issues with choosing this airport as the one for a major development.

The letter added: “Gatwick still operates as a point-to-point airport, with little connecting traffic and – despite Heathrow’s long history of constrained capacity – few long-haul routes which are not either to leisure destinations such as the Caribbean or Florida or to global cities and major hubs for which alternative UK connections also exist.”

The pair said by contrast Heathrow was one of the world’s most important aviation hubs and was also the most important freight airport in the UK.

The pair also addressed concerns that the expansion of Heathrow woud hurt regional airports, saying airports such as Birmingham, Manchester and Glasgow were increasingly “successful because they serve large catchments with growing economies, and because they are entrepreneurial and effective in attracting new carriers, not because Heathrow is constrained”.

In a speach given last month, Armitt, who now chairs the National Infrastructure Committee, said: “The delays over the last decade in the planning of new national airport capacity is one of the most obvious and often-quoted examples of the problems encountered with infrastructure decision making.

“It has taken far too long to reach a decision on a third runway at Heathrow: It has been 13 years since a statement of state policy in favour of the expansion of the UK’s principal hub airport, and three years since the Airports Commission reviewed the case in detail – we must make progress on this crucial project.”

MPs are expected to vote on the expansion of Heathrow in the coming weeks.