19/09/2012 15:29 BST | Updated 19/09/2012 17:23 BST

Cameron Drops More Heathrow Hints As Devolved Ministers Worry About Aviation Strategy

Downing Street has dropped yet more hints that David Cameron might consider going into the next election supporting a third runway for Heathrow Airport.

A communiqué issued by Number 10 on Wednesday lunchtime suggests Heathrow was near the top of the agenda when the prime minister met senior ministers from the Scottish, Welsh and Northern Ireland governments earlier in the day.

The meeting of the Joint Ministerial Committee held at Number 10 focused first on the stagnant economy, but the second item was the UK's future aviation policy. The communiqué reads:

Ministers .. agreed that aviation makes a strong contribution to economic growth in all parts of the UK and that it would be important to maintain connectivity between Heathrow, as the UK’s only hub airport and the rest of the UK and other initiatives to enhance connectivity.

There was no mention of alternate transport infrastructure methods like high-speed rail or more road-building in the note issued by Number 10, which will fuel speculation that Cameron is now focused on maintaining Heathrow's hub status.

Aviation experts believe only new runways at the airport in west London would ensure it remains a global hub, when faced with increasing competition from rivals in France, Germany and the Netherlands.

In the meantime certain slots between Heathrow and cities like Glasgow, Edinburgh and Belfast are regulated to some extent. Governments in the devolved nations are concerned that as Heathrow takeoff and landing slots become increasingly scarce, airlines will want to withdraw domestic routes in favour of more lucrative long-haul ones.

Although domestic flights into Heathrow are less profitable to airlines like British Airways than long-haul routes they do serve as feeders for the most profitable services. Their value was underlined by Virgin Atlantic's decision to start feeder services from Manchester to Heathrow from next year, a move the company said was in response to BA's near-monopoly on feeder routes from regional airports to Heathrow.

The government insists there will be no U-turn on Heathrow's third runway in this Parliament and in effect the decision was kicked into the long grass until after the next general election. A report by the respected economist Howard Davies is not due to complete until the summer of 2015, although Davies is expected to produce an interim report on aviation capacity in the south-east of England at the end of 2013.

The findings of that interim report could inform how the main parties write the transport sections of their manifestos at the next election. At the moment the three largest political parties all oppose the building of a third runway at Heathrow, though all say something has to be done about airport capacity around London.

There is spare capacity for aircraft movements at Gatwick and Stansted but neither are hub airports providing transfers between long-haul flights. Solutions to the problem of capacity at Heathrow range from building high-speed rail links to airports which have spare capacity to the construction of an entirely new hub airport somewhere to the east of London. All of the options come with political risks. MPs in and around west London believe they might lose their seats if a third runway went ahead, but many MPs around the Thames Estuary are equally opposed to a new airport being built there.

Justine Greening lost her job as transport secretary in Cameron's Cabinet reshuffle earlier this month, almost entirely due to her fervent opposition to a new runway at Heathrow. Greening, who represents Putney in southwest London, was moved to International Development, technically a sideways move but one that was widely seen as a sidelining.