Students in school uniform will be ushered out of a western Sydney shopping centre during class time as part of a new initiative to curb truancy.

Security staff at Blacktown's Westpoint shopping centre who see students in uniform between 9.30am and 2.30pm on school days will ask them to move on unless they have a leave pass.

"The basic philosophy is that if a child is meant to be at school and they are here in school uniform, we will be approaching them and encouraging them to be at school," Westpoint's executive property manager Tony Poile told AAP.

"We are not banning anyone or kicking anyone out. It's about addressing truancy as a problem and the police and Westpoint have discussed this measure as one way to cut truancy."

About 30 schools in the Blacktown area were involved in discussions about implementing the policy, which came into force on Monday, Mr Poile said.

An Education Department spokesman told AAP the initiative was not departmental policy but may have arisen from talks among local schools, shopping centre management, the local business chamber and police.

The Council of Civil Liberties is critical of the policy, describing it as "just stupid".

"(The policy) does absolutely nothing to solve a problem of truancy. All it does is shift it from Westpoint to elsewhere," council president Cameron Murphy told Fairfax online.

"Why would you be in uniform if you were a truant, anyway?"

It is not the first time shopping centres in NSW have implemented such policies, with shopkeepers in some centres refusing to serve students in uniform during school hours.

In other instances, shopping centres denied access to students before school to make sure they attended class.

Mr Poile denied the policy was introduced in response to truant students causing problems in the shopping centre.

He said there were no numbers available to indicate how many students would be asked to move along each day.

"We can either turn a blind eye to truantism or get involved... and be part of the community," he said.

"Even if we can get one or two kids back to school that makes it worth it."