The consortium is made up of authorities including Reigate and Banstead and Mole Valley.
Gatwick wants to increase passenger capacity to 74 million a year and bring its standby runway into use to cope with extra numbers.
That’s double the annual amount now.
The ten councils questioning the plans also say the transport network does not have the capacity.
Gatwick says the development will include amendments to taxiways, terminals and highways.
The proposals are currently in the government’s examination stage.
