BRUSSELS (AP) — Almost 20,000 Belgian trade union members mounted a demonstration on Monday to protest what they see as increasingly bad working conditions and the erosion of their right to strike. Action by transport workers paralyzed subway and other traffic in Brussels for most of the day.

The trade unions are irked by companies that seek to impose new contracts on workers that impact their social rights, affect their working conditions and cut their pay. They are specifically protesting the decision by the Delhaize supermarket chain to change the store management setup, directly cutting into the income and rights of staff.

Police authorities estimated the crowds walking through the capital at 18,000.

“We don't want second-class employees. We want respect and equal rights for all,” the socialist ABVV union said in a statement.

The unions are also protesting management measures to stifle strike action through court injunctions against the blocking of company premises, among other issues.

“The defense of our social and trade union rights is being made impossible,” the ABVV statement said.

Apart from public transportation, the day of protest could affect anything from day care centers to garbage collection.