Justine Greening fought the good fight as transport secretary, battling against the now inevitable expansion of London Heathrow Airport.

Elected by the constituents of Roehampton & Southfields, directly under the airport’s flight path, to stop the development, she was, perhaps, able to prevent the government offering the green light in this parliament. Nothing more.

Replaced on Tuesday in a cabinet reshuffle, Greening has been sidelined as the Conservatives prepare the ground for a u-turn on the issue.

Patrick McLoughlin, who will take over as transport secretary, has declared he has an “open mind” on the expansion of Britain’s only hub airport, joining chancellor George Osborne in a cabinet which increasingly favours a third runway, with the business case trumping environmental concerns.

While the party will suffer in seats close to the airport, they have calculated the economic recovery must take precedence.

The business community has been baying for additional capacity to connect to growing markets in Asia and South America for years, and it now seems certain the Conservatives will include support for a third runway in their manifesto for the 2015 election. 

Plan B

Of course there are other options.

Operating Heathrow as a ‘mixed-mode’ airport would increase capacity by as much as a quarter, but would again breach noise restrictions as planes approach from different directions.

Short-haul flights could also be barred from precious Heathrow landing slots, allowing only long-haul traffic to use limited resources. This might work in the short-term but is no panacea.

Gatwick could be expanded, or even Stansted, with second runways at either. But, in reality, the UK can maintain only one hub airport.

‘Heathwick’ – a high-speed rail link between Gatwick and Heathrow – was laughed off last year after being put forward by civil servants.

As for Boris’s fantasy island in the Thames? The problems are immense.

Not only is the planned location in one of the most congested flight paths in Europe, on the approach to Schiphol Airport in Amsterdam, that path covers five separate Special Protection Areas packed with wildlife.

Environmentalists could delay the project for years, while birds would also be hazardous to planes.

Funding for the £40 billion project is also far from assured, with some even suggesting a levy on planes landing at Heathrow could be imposed: a hard sell to British Airways, which would effectively be asked to pay for the demolition of its established base.

As for the transport connections? After the years it took to have Crossrail approved, it is hard to imagine Boris Island and its required infrastructure being approved by 2050, if ever.

Outspoken as always, Johnson rose to the challenge earlier, with a statement from the mayor exclaiming: “The third runway would mean more traffic, more noise, more pollution - and a serious reduction in the quality of life for hundreds of thousands of people.

“We will fight this all the way. Even if a third runway was built, it would not do the job of meeting Britain’s needs.

“If we are to remain Europe’s premier business hub we need a new four-runway airport, preferably to the east of London, that addresses the problem of aviation capacity before it is too late, and business is driven into the arms of our European competitors.”

With voters in the leafy suburbs of London ensuring his re-election in May this year, Boris is unlikely to change his tune any time soon.

Lack of Leadership

If the Conservatives were in a stronger position, i.e. not tied into coalition government with the Liberal Democrats, there is a chance prime minister David Cameron could change course and offer his support to a third runway tomorrow.

However, with the Lib Dems vehemently opposed, the political risk is simply not worthwhile. Disagreements over tuition fees, House of Lords reform and countless other issues have dragged the government toward disintegration, and this would be one bridge too far for Lib Dem leader Nick Clegg.

Instead, we get a government review of aviation policy which has been repeatedly kicked into the long grass. Delayed twice this year already, there seems to be little chance of a cohesive policy being put forward by the end of this year, at least.

If the UK cannot have a third runway, critics argue, at least offer a clear strategy of what a Conservative government would do instead.

It seems the party is merely keeping up appearances until it is in a position to chance course on the airport. Following today’s events, that time is moving ever closer.

Chris O’Toole