Complaints after pong wafts in from France

Large swathes of England were engulfed by a foul-smelling gas cloud which wafted over from France, triggering thousands of calls to the emergency services and the National Grid.

People in Kent, Sussex and Surrey first reported the smell after a discharge of the gas mercaptan from a factory in the northern city of Rouen drifted across the English Channel.

By yesterday afternoon the unpleasant aroma – similar to “rotten eggs” – had spread further up the country, with reports coming in from Oxfordshire and even as far north as Northampton.

The National Grid was inundated with more than 100,000 calls by 2pm, an “unprecedented” volume.

Mercaptan is added to municipal gas to alert people to gas leaks, among other uses, but is not toxic.