Transport bosses are considering introducing tolls on roads around Stansted Airport in Essex.
Council officials want to "explore the possibility" of charging motorists using roads leading to the airport, which is just off the M11.
Essex and Hertfordshire county councils believe that tolls may ease congestion near the airport. They want the government to fund research into tolls.
But campaigners against tolls say money should be spent on roads not research.
John McGoldrick, coordinator of the National Alliance Against Tolls, said: "Drivers are already paying £1bn a week in roads taxes.
"They don't need 'research into tolls'. They need more of the existing taxes spent on providing adequate roads and transport."