Protesters demonstrating against anti-protest legislation brought a sitting of the parliament to a standstill on Tuesday night before being removed from the gallery.

A police spokeswoman said about 20 protesters entered the public gallery and disrupted proceedings, causing the session to be suspended around 9pm.

At the time the upper house was debating legislation which would extend police powers to move protesters who block access to buildings or cause others to ''have a reasonable fear of violence''.

Anyone who ignores a ''move-on'' order could be arrested and face a $720 fine. Police would also have the power to obtain exclusion orders banning protesters from certain public places for 12 months.

Many of the protesters left the gallery once police and protective service officers arrived on the scene but three refused to move on and were escorted from the chamber.

The police spokeswoman said the three demonstrators would likely be charged on summons for refusing to leave the parliamentary precinct.

Jason Donnellan, one of the demonstrators who left the public gallery at his own accord, said the group was asked to leave after they called out "police state" during the debate. He said the security response was excessive and denied the group was disrupting the session.

Community and civil rights group have raised concerns about the "move-on" laws, and Australian Human Rights Commissioner Tim Wilson has called the laws ''excessive''.