Campaigners warned that David Cameron's crusade against health and safety legislation would lead to more workplace deaths as people commemorated Workers Memorial Day on Saturday.
Ucatt union construction workers gathered in London to watch stewards release 50 black balloons - one for each construction worker killed on the job in the last year.
By comparison, 46 British soldiers were killed in Afghanistan in the same period.
But despite clear workplace risks, Construction Safety Campaign's national secretary Tony O'Brian said on Sunday the government remained "hell-bent" on stripping away workplace protections.
Nearly two million people across Britain suffered from a work-related illness, he said and that figure was likely to soar with plans to cut the Health and Safety Executive's budget by 35 per cent over the next three years.
Meanwhile the Prospect union's Simon Hester said he felt angry as a health and safety inspector to see David Cameron denigrating his work, singling out a January letter to the Evening Standard in which the PM said he planned to "kill off the health and safety culture for good."
"I want 2012 to go down in history not just as Olympics or Diamond Jubilee year, but the year we banished a lot of this pointless time-wasting from the economy and British life once and for all," he wrote.
Mr Hester said the stance was "absolutely disgraceful."
"We're used to Richard Littlejohn and the Daily Mail. This is the Prime Minister attacking a key feature of looking after workers in this country.
"This is going to get people killed," he added.
Ucatt regional secretary Jerry Swain pointed out that last year had seen 2,000 major workplace injuries in the construction industry with 5,000 more considered "reportable."
He said an additional 5,000 people had been diagnosed with cancer linked to workplace exposure.
The figures were "horrific" and the government was ignoring them.
"They talk about freeing people up from the bureaucracy of health and safety," Mr Swain said.
"What they mean is the freedom of employers to kill their workers while increasing their profits."
Foreign Minister Alistair Burt's admission that the Cameron government has "supported" a survey of attitudes to US drone strikes in Pakistan's tribal areas amounts to a tacit admission of British involvement.
As Britain faces a new housing crisis we can learn from an occasion when tenants banded together to beat their landlord - and won new council housing
Iain Duncan Smith's brainchild came into force at the end of last month. It's bad news for almost everyone