THOUSANDS of people will rally across the United States tomorrow in defence of their trade unions, as the Supreme Court prepares to start hearings on a case that could deal a severe blow to unions’ funding.

The Working People’s Day of Action takes place in the run-up to Janus v AFSCME Council 31 reaching the court on Monday.

The case, brought by Illinois state worker Mark Janus but funded by groups linked to wealthy corporations and billionaires, threatens to make all state and local government workplace a “right to work” site.

Under “right to work” — which the unions call “right to work for less” — workers who benefit from trade union representation in bargaining negotiations can refuse to pay anything towards the union’s costs.

Under US law, a recognised trade union must represent all workers in a bargaining unit, but those workers don’t have to be members.

For 42 years, unions have been able to collect “agency fees” from those non-members to cover the cost of bargaining and enforcing contracts.

The Janus case threatens to put an end to that nationwide, not just in the 28 states that have adopted their own “right to work” legislation.

Workers in “right to work” states are paid less and are less likely to have employer-supported health insurance or pensions.

“This case is one of the most important cases to corporate interest groups,” said Celine McNicholas of the EPI think tank, which exposed the wealthy backers of the anti-union case.

“The outcome of Janus will affect millions of working people across the country and will impact the public services we depend on these workers to provide.”