The fate of a central feature of the government's transport plans - building of a third runway at Heathrow - is in the hands of a High Court judge. DAN COOMBS looks at where this highly contentious issue stands

AFTER a three-day judicial review, the hopes of supporters and opponents of a third runway at Heathrow Airport are in the hands of a judge.

Lord Justice Carnwath is expected to rule on the legality of the government's decision to allow construction of the runway, subject to planning permission, later this month.

During last week's hearing the High Court heard arguments from lawyers hired by councils and anti-expansion campaigners, while the government was forced to defend its decision.

Nigel Pleming QC, arguing the case for the anti-runway coalition, called for a fundamental review of UK aviation policy.

He described the government's consultation process, after which it announced its intentions last January to go ahead with Heathrow expansion, as 'cack-handed' and 'conspicuously flawed'.

Mr Pleming said the day before the then transport secretary Geoff Hoon made his decision, he had written to the Climate Change Commission (CCC) asking it to report on how the 2050 target to get aviation emissions below 2005 levels could be met.

The CCC eventually reported that the emissions growth envisaged in the 2003 White Paper was 'very substantially more than the level of growth consistent with the 2050 target'.

Mr Pleming said: "The CCC say there will have to be a massive diminution in air transport to achieve this, and yet the government is pressing ahead with expansion."

He argued that Mr Hoon should have waited for the CCC report before making his decision and had "got it all the wrong way round".

He said: "What was happening was actually a fudge. There was commitment towards Heathrow but real concerns about climate change.

"The government tried to stitch them together in a half cack-handed way."

Continued reliance on the 2003 White Paper was now 'untenable' and a fundamental review of UK aviation policy was necessary, he said.

With its two runways, five terminals and a maximum of 480,000 air transport movements (ATMs) a year, Heathrow Airport needs to grow to keep up with its European counterparts, according to the government and pro-expansion groups, who say otherwise it will be bypassed and marginalised, and jobs will be threatened.

Mr Hoon's decision to support in principle a third runway and sixth terminal was made subject to a limit of 605,000 ATMs, to be reviewed in 2020.

Integral parts of the decision were that additional flight slots would be 'green', available only to the most environmentally-friendly planes.

A target was also set for CO2 emissions by UK aviation to be reduced to 2005 levels by 2050.

Mr Hoon had presented support for the runway and the 2050 carbon emissions target as 'a package', argued Mr Pleming, but the implications of the green slots and the emissions target for Heathrow expansion were not consulted upon.

He asked Lord Justice Carnwath to quash the decision as unlawful and rule that it could not be retaken without a further period of full consultation with the public.

Jonathan Swift, for the Department of Transport, said the legal challenge to the third runway decision was misconceived.

Mr Swift said the consultation had met 'the basic requirements of procedural fairness,' claiming the challenge could succeed only if there had been a fundamental change after the consultation process, and this had simply not happened.

He said the government had consulted 'extensively on every contentious issue.

Air and noise quality could be maintained even with a large increase in air traffic movements, while it was made clear the airport operator would have to show how and where it would improve transport links in any planning application for a third runway, he said.

It was telling, said Mr Swift, that 'negligible space' had been given by the coalition's legal team in written papers challenging Mr Hoon's decision to the fact the three key conditions could be met.

Instead, he added, it was the consultation process itself that was wrongly under attack.

"Mr Hoon consulted extensively on the question of compliance with these conditions and reached a lawful and rational conclusion that they would be met," said Mr Swift.

He went on to say the conditions would be met even when Heathrow operated at a full capacity in 2030.