The Baird government was embarrassed into finally proclaiming the changes to the court security act on Friday, after questions by NSW Labor.

Parliament had approved extending the power of arrest to court security officers in 2011.

The change comes after Ali Hussein Chahine​ jumped the dock at the Downing Centre in October and assaulted two corrective services officers before escaping on a bus.

"The recent escapee at the Downing Centre was under the supervision and control of Corrective Services officers in court not sheriff's officers. If sheriff's officers were present they could have exercised citizen's arrest powers," said a spokesman for the Attorney-General, Gabrielle Upton.

The changes coming into effect on Monday gave court sheriffs certainty that they can arrest a person who commits an assault on court premises, he said.

"This will assist security officers to perform their role of protecting court personnel and court users more effectively," he said.

Shadow attorney-general Paul Lynch said: "The delay in commencing this provision is extraordinary. The torpor and disinterest by the government shows their lack of concern for security on courts despite all their pious rhetoric."

Ms Upton is the third Attorney-General in the role since 2011.

The Sheriff's Office is undertaking an ASIO review of court security to reflect the increase in the national terrorism alert level.

Labor says there is a shortfall in court sheriffs, with only 230 sheriffs to cover 154 local courts, which require two officers per court per sitting day. Mr Lynch says some regional courts are being left without sheriffs on duty.

An extra 40 sheriffs are being appointed this year, but the funding covers only one year.