A building contractor has received a formal warning from government health and safety inspectors for dangerous working practices.

Officials from the Health and Safety Executive (HSE) visited the site of a residential extension, in Partridge Close, Bushey Heath, after concerns were raised by a neighbour.

Peter Ashworth, of neighbouring Merry Hill Road, took a shocking photograph of one of the labourers balancing on a set of ladders, three storeys high.

A prohibition notice, which orders that certain aspects of working at height be stopped, has now been served on the contractors after an inspection was carried out on Monday, April 18.

HSE principal inspector Norman Macritchie said: "Working at height is one of the most obvious and well-known dangers on a construction site. More than 4,000 British employees suffered serious injury after falling from height in 2008/09.   

“A lax attitude to health and safety in one of the more dangerous industries is not acceptable, especially when so many potential life changing injuries are completely avoidable by taking common sense actions and precautions. As always, HSE will not hesitate to take action if we find poor practice that is putting lives at risk.”

Despite the notice, the contractor in entitled to carry on working at the site, provided it is not in breach of safety regulations.

An inspector will make a follow-up visit to the site, to ensure the standards are being met.

The contractor could also face a fine for the incident.

There have been 14 recorded incidents of workers falling from a height of more than two metres in the Watford area, since 2001/02.

Officers from Hertsmere Borough Council's building control department initially visited the site on April 11 and issued the contractor with an informal warning, before passing the matter to the HSE.

The contractor now has 21 days to appeal the notice.

The extension courted controversy earlier this year when the owners were forced to re-apply for planning permission after they built beyond the permitted designs.

Dozens of neighbouring residents fought the application, describing the large property as a "hideous, bark-like building", but councillors passed the plans in March.