Nearly a quarter of building sites in London have failed to meet minimum health and safety legal standards.
More than 400 sites were visited by Health and Safety Executive (HSE) inspectors between 18 February and 15 March.
A total of 93 of the 401 sites failed to meet minimum standards.
An HSE spokeswoman said: "Performance remained mixed. There were some signs of improvement. But some inspectors found worse standards."
The inspections were part of a national HSE clampdown aimed at reducing death, injury and ill health.
The building sector features consistently in the top three high-risk industries for deaths and injuries, according to the HSE.
Inspectors made unannounced visits to ensure companies are managing high-risk activity, such as working at height.
They also checked for general good order, assessed welfare facilities and checked for whether personal protective equipment, such as head gear, was being used appropriately.
Specific work activities on some of the sites were deemed to be so dangerous that immediate prohibition notices were served by inspectors, halting further work until standards had been raised.
Andy Beal, a principal inspector for construction in London, said: "It's good news that the majority of the construction sites we visited were obeying the law but sadly a sizeable minority sites are letting down the rest of the industry."
- 27 March 2013
- 23 January 2013
- 6 August 2011