Employers who commit "wage theft" by underpaying their staff could face jail time under a NSW Labor Government, Opposition Leader Luke Foley has declared.

Mr Foley on Saturday told the NSW Labor conference guilty employers could also be fined under new legislation to criminalise the deliberate failure to pay wages and entitlements.

It would deal with situations like those involving the 7-Eleven chain, where many workers were not paid correctly and records were falsified.

"Our laws won't apply to genuine mistakes," Mr Foley said. "Employers who do the right thing will benefit as they won't be completing with under-cutting cheats."

"But we'll go after that minority whose business model is based on exploitation."

Mr Foley said a Labor Government would also overhaul laws to make head franchisors liable for employment conditions in their networks, and widen the powers of workplace inspectors to recover unpaid wages and entitlements.

A licensing scheme for labour hire companies would include a fit and proper person test for operators, owners and directions, Mr Foley said.

Sanctimonious bulls***

The opposition leader, who also described plans to legislate Sunday penalty rates and allow plebiscites on demerging councils, addressed the conference after a morning marked by factional disagreements.

In a speech later described by Senator Sam Dastyari as a "load of sanctimonious bulls***", senior union official Tim Ayres criticised the decision to have former senator Graham Richardson deliver the life members' address on Sunday.

Mr Richardson, a key factional leader during the Hawke-Keating years and former boss of the NSW Right, was once widely feared as a number cruncher and fixer.

"Graham Richardson was an old warrior of the cold war Labor Party," Mr Ayres said on Saturday. "We shouldn't glorify some elements of our history."

Senator Dastyari, who earlier this week defended Mr Richardson to Fairfax Media, congratulated Mr Ayres on "being pre-selected by a faction for a Senate position that isn't yet vacant".

He also took aim at leaks he said "undermined" the conference, telling delegates he was angered by recent media reports on branch finances.

"It achieves nothing – nothing – but help our conservative opponents," Senator Dastyari said.

Domestic violence leave

The conference, which continues at Town Hall on Sunday, is debating a range of workplace relations issues including 10 days domestic violence leave.

Delegates are expected to endorse a motion by the Australian Services Union in support of a minimum 10 days paid domestic violence leave to be enshrined in the national employment standards.

Federal Labor promised in 2015 it would legislate for five days family violence leave.

Federal Labor leader Bill Shorten will address the conference on Sunday when he is expected to outline a federal Labor government's broad approach to tax as well as flesh out a new policy on taxing trusts.