Blue labour is a grown-up idea about jobs and workers that talks about the problems that sometimes happen between the people who hire workers and the workers themselves.
When somebody is talking about "blue labour," they're usually talking about working-class jobs that require a lot of physical labor - like building things, working with machinery, or even manual labor jobs like construction. These jobs are sometimes called "blue-collar jobs" because workers typically wear blue uniforms or coveralls to do them.
Now, the reason blue labour is important is because sometimes the people who run these jobs - the bosses or the owners of the companies - don't treat the workers as well as they should. They might not pay the workers enough money, or they might make them work very long hours without breaks. They might not give them good working conditions, or they might not let them have enough time off to be with their families.
This can make it really hard for workers to do their jobs well, because they might be tired, or stressed out, or hurt. It's also really unfair, because these workers are doing important work that helps other people - like building houses or fixing cars.
So, when somebody talks about blue labour, they're usually talking about trying to make things better for these workers. They might want to make sure that the workers get paid a fair wage for their work, or that they get good benefits like health insurance. They might also want to make sure that workers have a voice in how the job is run, so that they can help make things better.
Overall, blue labour is just a way of saying that we need to all work together to make sure that workers in these important jobs are treated well and given the respect they deserve.