A group of residents from east London are taking a council to court over a decision to allow 50% more flights a year from London City Airport.
In 2008 Newham Council gave the airport permission to increase the number of annual flights from 80,000 to 120,000.
But residents formed action group Fight the Flights and are trying to overturn the decision at the High Court.
They argue new flights will increase noise and pollution. The council said it could not comment for legal reasons.
Fight the Flights chairman Anne-Marie Griffin said: "We have worked tirelessly for the past three years to stop the expansion of this airport, which already causes so much disturbance and pollution.
"This hearing will allow those who were not consulted, and those who were not listened to by Newham Council, a chance of justice."
The residents will be represented in court for the two-day hearing by Friends of the Earth.
Gita Parihar, acting legal head at Friends of the Earth, said: "We believe Newham Council has acted illegally by failing to adequately consult on its proposals and failing to consider government policy on tackling climate change."