Several hundred construction workers have gathered outside the Federal Magistrates Court in Brisbane to voice their objections to a case against unionist Bob Carnegie.

Carnegie is facing 52 charges of contempt of court relating to industrial action last year at the site of the new Queensland Children's Hospital under construction at South Brisbane.

This morning several hundred construction workers gathered to support him outside the court where the charges are being heard.

Community activist Tom Bramble who helped organise today's protest says Carnegie's role in leading the nine-week strike should not be punished.

"Workers should be able to organise strikes and picket lines without the threat of million-dollar fines or a six-month jail sentence," he said.

Carnegie has pleaded not guilty to the charges.

The hearing continues.