The proliferation of neon signs, garish paint and advertising boards is threatening to ruin a leading tourist area, according to an influential watchdog body in central London.

The Covent Garden Area Trust has commissioned a special report that will focus on how to stop the area from sliding into seediness, as more shopkeepers and traders use visual gimmicks to attract customers.

Covent Garden attracts visitors from all over the world to see premier attractions such as the Royal Opera House and the London Transport Museum. It is famous for its lively shopping area, with specialist shops, a mass of pubs and restaurants, as well as street entertainment.

However, according to Leana Pooley, the Covent Garden Trust administrator, shops and restaurants are so desperately vying for customers' attention that they resort to every means possible - including bright lights, posters and advertising boards propped up on the kerb - with no thought to the effect on the area as a whole.

'It should look like St Mark's Square in Venice,' said Miss Pooley. 'But there is a forest of bay trees, the most revolting window boxes made out of plastic and filled with dead-looking geraniums.

'It is a mass of different kinds of tables - people just put out old white plastic garden things. The whole thing is totally unco-ordinated. It looks so untidy.'

The trust, which took over many freeholds in the area after the Greater London Council was abolished, is producing the report with the aim of encouraging traders and shopkeepers to maintain the area's architectural and historical character.

It has commissioned a study by Civic Design Partnership, a team of conservation specialists which recently advised on the Seven Dials area. Over the next four months they will carry out an audit of the area, compiling details of each building's history and advising on street furniture, paintwork and decorations to maintain the appropriate character.

Peter Heath, senior partner with the firm, said they will look at every building and report on appearance. 'From that, we will be looking at whether the streets are as they were intended when they were preserved or whether they have been in anyway altered by the changing use and intensity of use. The end product will be a handbook that is a specific reference book for Covent Garden. It will tell people what is best for the buildings.'

One problem, he said, was the proliferaton of unlawful structures and signs. 'It's something people associate with a shabby area and once started the effects can get out of control.'

Miss Pooley agreed: 'We have to think about who we are attracting. If we make is so tacky we are going to attract the sort of people who go to fairgrounds. The people with money are going to go to Bond Street, not here.'

A reception to discuss the study will be held on Wednesday 19 October at 5pm in McCormick Hall, The Crypt, St Martin-in-the-Fields, Trafalgar Square.