Coventry Airport has taken its fight to build a new passenger terminal to the High Court.
Lawyers for the airport's owners have begun a five-day appeal against a 2007 government decision which blocked their bid for a permanent terminal.
A public inquiry found a new terminal on the Baginton site would have an adverse impact on noise in the area.
But the airport claims the decision was legally flawed and says the terminal would be good for the region.
If the airport's challenge is successful, its planning application will be reconsidered by government ministers.
The airport has been trying to expand its facilities on the site for the past five years.
The expansion plans have the backing of business leaders in Coventry but have fallen foul of the planning authority, Warwick District Council.
Airport protesters say the new terminal, which would be able to handle up to two million passengers a year, raised issues of noise and pollution