The steelworkers union had hoped for a show of strength in numbers Tuesday as it goes to court to try to block U.S. Steel from moving production out of Canada. Now, they've been told the court won't hear the case until Thursday.

The United Steelworkers (USW) is calling on workers and pensioners to show up outside Ontario Superior Court House on Thursday but are not yet sure at what time. 

"While the date of court proceedings has changed with little notice, our members, retirees and supporters are ready to join us on Thursday, or any day, any time, to fight for the pension contributions and health benefits they have earned and that they deserve," said Gary Howe, President of USW Local 1005 in Hamilton said in a press release.

On Thursday the union will argue that the steelmaker should be barred from exporting its highest-quality steel production to the U.S. It will also argue against the company's request to stop paying employee health benefits to its pensioners.

"Our goal is to protect our retirees," said Tony DePaulo, assistant to the USW Ontario director.

The union hopes to bring attention to the cause with a big turnout, he said. The group will assemble outside the courthouse at 330 University Ave. in Toronto.

"Let's fill the court house and let them know this is unacceptable," the union says in its call to action.

The court appearance comes after three days of mediation between U.S. Steel and several stakeholders, including the union and the city of Hamilton.

U.S. Steel Canada is in Companies' Creditors Arrangement Act (CCAA) protection right now as it restructures or finds a willing buyer for its Hamilton and Nanticoke operations. That protection ends Dec. 11, but the company wants an extension.

As part of that request, the company is asking for permission to suspend paying certain pension contributions, health benefits to pensioners and its property taxes. As of Tuesday, city finance officials say they still aren't sure the steelmaker wants a deferral or an exemption. 

For its part, U.S. Steel Canada said a court-ordered extension would protect workers. Without it, president Michael McQuade said this month, it would have to close its Canadian operations by the end of the year. 

"With a court order we can preserve work and meet obligations to approximately 2,200 employees and continue to deliver high-quality steel products to our customers from our two Canadian steelmaking facilities," McQuade said. "The court order, if granted, would also provide additional time to find a consensual restructuring solution, and to conduct a new Sale and Restructuring Process when market conditions improve."

With files from Canadian Press