The construction workers are the first to arrive in Collins Street. Delegations have come from construction sites around Melbourne’s CBD to support 75 power station workers from Yallourn, locked out eight weeks ago.

Three bus loads of Yallourn workers and their families arrive. They’ve been maintaining a round-the-clock protest camp outside the power station for the eight weeks of the lockout. Today, 16 August, they’re in Melbourne to protest outside the local headquarters of China Light and Power (CLP), the Hong Kong-based company that employs them through its subsidiary Energy Australia. CLP last year reported a profit of more than $1.2 billion.

I interview Luke Van den Meulen, the Victorian secretary of the Mining and Energy Division of the Construction, Mining, Forestry and Energy Union (CFMEU). He explains that conditions were stripped out of the Yallourn enterprise agreement in a bitter industrial dispute over a decade ago. It leaves the workers with no job security, no consultation clause and no guaranteed staffing levels at a time of dramatic change for the brown coal-fired power industry. Even if the workers win all their current claims, this will be still be the worst enterprise agreement in the La Trobe Valley, where many workers – if they survived the destruction of good secure jobs during the privatisation of the power stations 20 years ago – still enjoy reasonable levels of protection.

By now we’ve been joined by delegations from climate change activist groups and other unions. Maybe 500 of us march up Swanston Street.

As we march, I chat with the son of one of the locked out workers, who describes the stress of completing year 12 while his family worries about where the money is coming from, week to week. A Yallourn worker explains that the company outsources its workforce in maintenance and in the coal mine that feeds the plant, to avoid any responsibility for them – “a bit like the government outsourcing all the refugees to PNG”. The powerful outsourcing their dirty work and their responsibilities is nothing new.

We stop outside CLP headquarters. John Setka, the secretary of the Construction Division of the CFMEU, gets a great response when he tells the crowd that behind the 75 Yallourn power workers stands every one of the more than 100,000 members of the CFMEU. Renegade priest, Father Bob Maguire, reminds us that workers, not corporations, are the source of all wealth. Activists from Environment Victoria and Friends of the Earth pledge their solidarity with the workers – any transition to a clean economy has to enshrine rights for the workers or it will never happen.

The secretary of the Queensland ETU talks about the regular financial contributions heading to Yallourn workers from Queensland power workers, who are facing the destruction of their industry at the hands of Campbell Newman. Easily the two biggest cheers of the day come right towards the end. Veteran unionist Dave Kerin asks if we are prepared to travel to Yallourn and picket in solidarity with the locked out workers. A huge roar of approval is the response. Then John Setka returns to the microphone to announce the news that Bob Carnegie has had his charges dropped. After a long campaign, union solidarity has won out against one of the biggest companies in the land. The parallel isn’t lost on anyone.