Excelsior argues the films are widely available in the high street

The erotic DVDs are available in the gents' toilets of two outlets in Gloucester and one in Cheltenham.

The pubs, operated by Gloucester-based Excelsior Leisure, are among 30 across the country taking part in the scheme run by a London company.

Excelsior spokesman Stuart Hayles said the pubs were for over-18s only.

He pointed out that the films only contained soft-core material and were readily available in many high street stores and on multi-channel TV.

'Public image'

"To a certain extent, there is much more control in a pub where there are restrictions on age and access," Mr Hayles said.

But the scheme has been criticised by pub industry groups.

Is it really appropriate to the standard-raising approach we are putting in across the board? Christine Milburn, communications manager, BBPA

Christine Milburn, communications manager for the British Beer and Pub Association (BBPA), questioned whether it was the right move at a time when the industry was trying clean up its act.

"What sort of image is this presenting the public?" she said.

"Is it really appropriate to the standard-raising approach we are putting in across the board?"

The trial, believed to be the first of its kind, is being operated by a firm called Tongue in Cheek.

It will run until the end of July, after which the company will decide whether to roll out the machines nationally.