The Green Party has accused London Mayor Boris Johnson of a crude attempt to cut targets to reduce carbon dioxide emissions by proposing a new airport off the north Kent coast.

London Assembly Green member Darren Johnson said he would be pushing for an explanation why the airport plan was needed.

He said: "The Mayor has committed to working to cut London’s CO2 emissions by sixty per cent by 2025. Effectively moving Heathrow to outside of London looks like a crude attempt to export London’s CO2 emissions instead of trying to reduce them."

He added: "Instead of pursuing madcap ideas to move Heathrow airport to an island in the middle of the Thames, the Mayor should be looking at how we can reduce the volume of air traffic at Heathrow in order to cut emissions, cut air pollution and cut noise levels."

In a question tabled by the Green party at the Greater London Assembly, the Mayor agreed to meet the Royal Society for the Protection of Birds to discuss its concerns over the impacts on migratory birds and the legal protections which cover wildlife on the proposed site of the airport.

• KCC leader slams Boris' airport plan >>>

• Kent boss backs Boris over airport plans >>>

• Plans to build 'Heathrow overflow' off Sheppey >>>