TWO LEGAL challenges to the government's airport expansion plans were launched at the High Court this week.
Local authorities and antiairport expansion groups began separate actions to halt expansion of Stansted, Heathrow and Luton airports.
Although separate, both claims cover similar issues.
Hertfordshire and Essex County Councils are leading local authority opposition to expansion at Stansted and Luton.
They claim that operator BAA would need to use revenue from its Heathrow and Gatwick airports to fund the Stansted scheme.
This is illegal under Civil Aviation Authority rules. Antiairport campaign groups won the right to a judicial review of plans to expand Heathrow, Stansted and Luton earlier this year.
Both groups also complain about the lack of consultation over the Luton proposals and the absence of environmental impact assessments.
The Future of Air Transport White Paper published last December proposes new runways at Stansted by 2012, and at Heathrow by 2020, as well as a 1km extension to the Luton runway.
These are considered necessary to meet an expected threefold increase in passenger numbers over the next 30 years.
The hearing, scheduled for six days, started on Monday and a ruling is expected in February.
No court has ever overturned proposals contained in a White Paper.