A construction worker was found dead at the bottom of a lift shaft in offices in central London last week.
The unnamed man worked for specialist joinery and fit-out contractor Swift Horsman.
That means six construction workers have been killed at work in the last three weeks.
There have been five deaths in London where workers were killed in Elephant and Castle, Kingsway and Upper Thames Street.
A road gang worker was killed on the A2. In Shropshire, a builder was also crushed to death under 20 tonnes of rubble.
Alan Ritchie, general secretary of Ucatt union, said, “This latest tragedy underlines the unacceptably high level of deaths in construction. Many companies remain blasé about health and safety.
“The whole industry must make the safety of workers a key issue. If we don’t then workers will continue to be killed at this alarming rate.”
There have been 30 deaths so far this year. If trends continue then deaths could increase above the 77 workers killed last year.
Alan Ritchie, added, “It is shocking that 30 construction workers have already been killed at work this year.
“If this was any other profession it would be front page news. This is a national scandal. Action must be taken now to stop killer bosses.
“The number of workers killed must not be allowed to rise even higher than last year’s astronomical level.”