A number of trade union organisations have joined the campaign to oppose the new €100 household charge.
UNITE, which represents 50,000 members, is asking people not to pay.
The Civil and Public Service Union (CPSU) and the Dublin Council of Trade Unions are also opposing the charge.
So far around 260,000 of the 1.6m eligible households have signed up to pay the charge, with just 11 days to go to the March 31 deadline.
A national protest organised by opponents to the charge will take place at the National Stadium on Saturday.
Des Derwin from the Dublin Council of Trade Unions admits his organisation is asking its members to defy the law.
"It's always been a tradition… that (the breaking of) certain laws and civil disobedience have had their place so it's in that tradition," he said.
"And part of this is that we are against the household and water charge," he added.
"We regard it as a stealth tax, another charge on workers."