LONDON (Reuters) - London is to set up open-air urinals to stop the rot that is threatening one of the city's most famous tourist attractions.

Westminster City Council, which runs the centre of the British capital, has acted on evidence that urine was eroding the National Gallery in Trafalgar Square.

"Night-time revellers, waiting at a bus stop outside the gallery, have been relieving themselves against the new wing," the council said in a statement.

"The gallery now fears that the stone of the building is being affected by uric acid."

Even though the council provides more public toilets than any other local authority in Britain, urinating in public is widespread throughout the West End, the centre of London's nightlife.

"Much of the West End is now blighted by this type of...anti-social behaviour," the council said.

"The urinals will be placed in problem areas where `wetspots' have been identified or where residents and businesses have raised concerns."

The new, partially-enclosed lavatories, based on the French model, are being rushed into service in July, months ahead of schedule, because of the scale of the problem.

The council consulted authorities in the Netherlands, where street urinals are already a common fixture in cities like Amsterdam.