Motorists will be left in the dark next week in a bid by highways chiefs to go green.

Lights on the M2 are being permanently switched off in the early hours in a move to reduce carbon emissions and light pollution by 40 per cent.

The lighting between junction 3 for Chatham and junction 4 for Gillingham will be turned off between midnight and 5am from Thursday, May 7.

The motorway junctions and their approaches will remain lit.

The Highways Agency says the site has an excellent safety record and a very low traffic flow at these times, and has been chosen after careful assessment.

The stretch of motorway is one of four across the UK to be selected for the lights out plan. Two more are expected to follow.

Jon Griffiths, Highways Agency network operations director in the south east, said: "We are looking for ways to reduce the carbon footprint of operating the motorway network and this is one step in that direction.

"We expect to achieve up to a 40 per cent saving in carbon emissions and energy use for each section of motorway where we do this, and local communities will benefit from reduced light pollution of the night sky.

"We have carefully chosen sites where the traffic flows are so low in the early hours that when taken together with the good safety record of the sites, there would be no case for installing new lighting if the decision was based on the overnight figures alone."

Timing devices at the roadside will control when the lights switch off and on again and the Highways Agency can override the mechanism if needed.