KEY POINTS:
A group of New York taxi owners is suing the city over a plan to turn the entire fleet of cabs "green" by 2012, saying the plan compromises safety and is unconstitutional.
Under the plan, promoted as an environmental model for other large cities, every new taxi must get at least 100km per 7.8 litres, a target now met by hybrid and clean diesel cars.
The Metropolitan Taxicab Board of Trade, an association of taxi owners accounting for about a quarter of the city's 13,000 yellow cabs, filed a complaint in Manhattan federal court seeking an injunction to halt the regulation.
The city is reported to have about 1400 hybrid taxis already.
