Mayoral candidate says London needs to do more than 'merely' protect environment in Conservative Party conference speech
New standards will lower the legal limit of the smog-causing pollutant from 75ppb to 70ppb
Personal air quality monitor uses ambient energy from wifi and mobile networks to track pollution data
Company confirms around 500,000 Volkswagens and 400,000 Audis involved in emissions scandal
Diesel emissions-rigging scandal continues to deepen as Audi admits using 'defeat devices' in 2.1 million cars
Department for Transport to compare laboratory tests to 'real world driving emissions'
Countries publicly calling for investigations into VW emissions rigging scandal have privately fought to keep loopholes in car tests for carbon emissions
Martin Winterkorn says he is shocked by events of past few days and hopes to provide auto giant with fresh start by resigning
Environmental Audit Committee chair Huw Irranca-Davies says diesel drivers need assurances they have not been deceived by automakers
VW says 11 million vehicles globally fitted with defeat device, which helps cars pass emissions tests