An area used for testing air quality has been expanded after recent tests found high levels of nitrogen dioxide in a major road.

Sevenoaks District Council made the decision after tests revealed levels of the toxic gas exceeded Government targets in parts of the A20 between Swanley and Farningham.

The Air Quality Management area which covered London Road and Bartholomew Way, Swanley, has now been stretched to include the A20 and Main Road in Farningham.

Council cabinet member for air quality Councillor Keith Loney said: "We have a duty to assess air quality and draw up action plans where we establish there is a problem.

"In every case poor air quality is associated with the use of motor vehicles. Therefore, we could all make a difference by, where possible, using our cars less and walking, cycling or using public transport."