Even children and pensioners mock the Royal Botanic Gardens Constabulary as they do their rounds in the green electric buggy, it has been reported.

The �14,000 four-seater vehicle was introduced to patrol the 300-acre site in west London because it was environmentally friendly and quieter than other vehicles.

But it was reported in the Police Review magazine that it has made a mockery of officers.

Our police don't need to get across the gardens at incredible speeds. It's not like they are going to be chasing plant thieves around

Kew Gardens spokeswoman

One unnamed officer said: "While taking out the vehicle for a test drive around the gardens, everyone from garden staff to schoolchildren and OAPs started laughing and jeering when they saw us in it.

"Despondence, disillusionment and ridicule are just some of the experiences and feelings officers get with regard to this vehicle."

John Macready, of the Public and Commercial Services union said some members had expressed concern about whether the buggy was "an authoritative vehicle for officers to drive".

But a spokeswoman for Kew Gardens said that the gardens were supposed to be a peaceful haven so it had been decided to introduce quieter and greener vehicles.

She added: "Our police don't need to get across the gardens at incredible speeds.

"It's not like they are going to be chasing plant thieves around.

"I think the vehicle is lovely, and it gives out all the right environmental and safety messages to our visitors."