It's one rule for them, and another for the rest of us.

Trudie Styler, wife of Sting and self-styled eco-warrior, recently took a helicopter to travel 80 miles from Wiltshire to Devon, a journey that would have taken less than two hours by train.

The actress and film producer is forever harping on about saving the environment, having set up the Rainforest Campaign in the late 1980s with her pop star husband.

The Stings are known for eating only organic food, supposedly grown on their land, although one member of staff recently admitted to serving up nonorganic salad from the supermarket.

So what was Styler thinking as she clambered into her gas-guzzling chopper, off to stay with friend and fellow greenie Zac Goldsmith on his organic farm in Devon?

Her own home, Lake House, a Jacobean manor in the Avon Valley, is conveniently located just six miles out of Salisbury, from where frequent trains run to the West Country.

On Monday David Cameron announced plans to crackdown on domestic flights by slapping a green tax on them, so perhaps Styler is enjoying the luxury of a private helicopter while she can get away with it.

But this isn't the first time the Stings have been caught out. In 2000 the couple threatened the Ministry of Defence with legal action if a nearby airfield were to be expanded.

It later emerged Sting had twice used the airfield in question from which to roar off in his private jet.

Styler's personal assistant declined to comment on her boss's travel arrangements when I called.