Demonstrators complain that their working conditions have worsened significantly in recent years.
Belgian workers took to the streets of Brussels on Monday, as they protested against "attacks on the right to strike".
The demonstration saw up to 20,000 people take part in the general strike that was called by unions after the federal government announced its intention to go ahead with a new law banning rioters from taking part in protests.
Many workers taking part dressed themselves in prison costumes to illustrate their point.
"This is what is likely to happen if we do not hurry to block the laws that are being put in place," Philippe Barbion, from the FGTB union said.
"Today, the fact of demonstrating, of negotiating becomes repressed by the law and therefore today, we wanted to show that if we do nothing, tomorrow we will go to demonstrate, we will all go to jail."
Demonstrators are also angry about a series of recent judicial decisions that oblige protesters to lift their blockades in front of Belgian supermarket chain Delhaize. Their protest, against the franchising of the company, has been ongoing for three months now.
Olivier Lecomte, permanent secretary at the CGSLB union, told Euronews that the government's proposed law could perpetuate these types of practices against picketing.
"Between protesting and blocking a company in the context of discontent - and breaking it - is totally different," he said.
Corinne Sachot, a caregiver who took part in the protests said that she is simply exercising her right to strike.
"We are not here to vandalise. We are here to claim our rights. It's not the same thing," she told Euronews.
The demonstrators have called what is happening in Belgium "social dumping", saying that they will continue fighting against it, otherwise it will likely spread to other sectors.