SYDNEY - Almost 400 public servants in Australia's New South Wales (NSW) has joined a protest in west of Sydney against changes to the state's industrial relations laws, local media reported on Tuesday.

More than 350 nurses, police officers, firefighters, teachers and other workers in the public sector marched through Penrith on Tuesday against the legislation that restricts wage increases, according to Australian Associated Press (AAP).

The bill allowing the government to cap annual wage rises for public servants at 2.5 percent passed in June.

NSW Opposition Health Spokesman Andrew McDonald said the rally was timed to mark NSW Premier Barry O'Farrell's 100th day in office.

"The biggest thing Barry O'Farrell has done since becoming premier is ripping away the rights of public-sector workers," said McDonald, who joined the rally.

"Today's protest sends a very clear message to the O'Farrell government that the workers our community relies on will not idly stand by while their rights and conditions are ripped away."

About 50 nurses from Nepean Hospital who voted to stop work joined the rally at midday.

Further nurse protests are planned at Orange and Bathurst in the state's central west this week, NSW Nurses Association (NSWNA) assistant secretary Judith Kiejda told AAP.