Melbourne's CBD came to a standstill for a union-led rally of up to 10,000 protesters calling for safer Victorian building sites.
Building company Grocon, the state government, WorkSafe and the media were all in the firing line at Tuesday's protest, organised by the Construction, Forestry, Mining and Energy Union (CFMEU).
A banner reading "Safety for Grocon workers now" fronted the rally, which was flanked by dozens of police who diverted vehicle and pedestrian traffic.
The crowd marched from Trades Hall, pausing at two Grocon sites where a total of four people have died in recent months, to WorkSafe Victoria's headquarters.
CFMEU Victorian secretary John Setka accused the state government of covering up safety concerns.
Its response to last month's Swanston Street brick wall collapse that killed three pedestrians was inadequate, he said.
"We're not going to let them sweep this under the carpet."
Mr Setka said the attendance was "awesome" given what he called "bull**** peddled by the media" about the rally and the motivation for it.
Victorian Premier Denis Napthine accused the CFMEU of politicising the wall collapse and branded the rally "utterly disgusting and unacceptable".
"They are clearly trying to disrupt construction and building across Victoria. They are running a politically based union campaign, and they should not be using the deaths of innocent people in that process," he told reporters on Tuesday.
Some protesters booed as they passed the Grocon-managed Emporium building site, before being called to calm by organisers.
A union-led blockade at the Lonsdale Street site in August led to clashes with police, and a worker fell to his death from a crane at the site in February.
Grocon said the union was manipulating the issue of workplace safety.
"Today was simply another chapter in the CFMEU's campaign to `smash Grocon' because we've refused to let them control our building sites," a company statement said.
"Despite the recent tragedy, the CFMEU knows Grocon's safety record is among the best in the industry."
Police praised the crowd for rallying peacefully, with a spokeswoman saying no arrests were made.
WorkSafe has stressed its investigation into the causes of the wall collapse will not be jeopardised by public pressure.
Its health and safety director Jarrod Edwards said injuries on construction sites in the state had fallen by 3.5 per cent in the past 12 months.