In 2009, I was the chair of the Competition Commission inquiry that ordered BAA to sell Gatwick and Stansted, two of its three major London airports, retaining only Heathrow.  We found that the common ownership by BAA of these airports, Heathrow’s position as the only significant UK hub airport, and aspects of the planning system, government policy and airport regulation all had an adverse effect on competition.

At that time, Heathrow accounted for the Commission believed that increasing competition between these airports under separate ownership would have a positive effect on capacity and route development, service levels, product innovation, and pricing. We expected some of the benefits from competition to manifest themselves immediately but to increase over time.

And so it has proved. Investment levels at Gatwick and other airports have increased markedly, the number of direct international routes from many UK airports – not just Heathrow – has increased, including to Asia, the Middle East and North America, and the passenger experience at UK airports has improved.

Airport charges have generally remained steady; at Gatwick, passenger charges have actually fallen - from £8.84 in 2014 to £8.61 in 2015 - and are among the lowest in Europe. In contrast, the authoritative Leigh Fisher survey of the world’s top 50 airports reported that equivalent charges at Heathrow in 2013 and 2014 were respectively £24.18 and £26.23, the highest of all their airports.

It is clear, therefore, that following the ownership changes required by the Competition Commission, the UK airports market has developed and diversified in ways that were hoped for but that in practice could only be realised by the subsequent investment and other decisions taken by airport owners and managers.