• JE Kirby rightly complains about London buses stopped with their engines idling for no good reason, adding to pollution, (Bus drivers, turn your engine off when you’re idling at stops, June 8).

Walking or cycling around the borough I see countless diesel vehicles parked with their engines idling, the driver usually busy on the phone.

There seems to be no awareness of the unnecessary pollution being caused. You would think the price of fuel might make them switch off.

In Switzerland, for example, it’s illegal to be parked with the engine running. Why not here?

MICHAEL GRAHAM
St Paul’s Road, N1