With the Green Party Trade Union Group holding its first national conference in Brighton this weekend, it seems as though finally the Green Party has become the true home of the Labour movement.
The slowly souring relationship between the Labour Party and the Trade Unions (we'll see the latest chapter of this story play itself out next week when local government workers walk out on strike at the Government's latest poverty wage settlement for public sector workers) is reminiscent of that between a victim of domestic violence and her abusive partner: however much the Labour government abuses the unions their members struggle to walk away that final time.
But all this is beginning to change as unionists increasingly recognise that the Green Party's record of championing Trade Union priorities, from defending public services from privatisation through to promoting a Living Wage, demonstrates that they are the real party of social justice.
The fact is there is no contradiction between policies to save the planet and policies to protect workers' rights.
And the stark reality is that climate change is not just an environmental issue: it's a social issue, and it's the world's poorest that will pay the heaviest price.
Taking steps to cut carbon emissions could create thousands of new jobs. A recent study by the European Trade Union Commission found that job opportunities were likely to rise if governments cut emissions, and that moves towards a zero carbon economy can be ones that enhance employment.
A zero-carbon world is a labour-intensive world. Some jobs would certainly be lost in some of the more carbon intensive industries, but these would more than be made up for by new jobs in an economy based on repairing, recycling, and re-use.
Greens and Trade Unions are working ever-more closely together as we realise we share strong principles of social justice, wealth redistribution, public services and sustainability - and that we are prepared to argue for them and to be prepared to stand up for them, clearly and strongly.