Trade unions will protest at the Sydney headquarters of the Lipton tea company over what they call the company's "shameful treatment of workers" in Pakistan.

Unions NSW says 723 casual employees at the Khanewal factory are being exploited over a range of issues including pay, job security and leave entitlements.

Protesters plan to descend on the Epping headquarters of manufacturing giant Unilever, which owns Lipton, at 11.30am (AEST) on Thursday.

"Unilever is on notice, Australian unions will not tolerate blatant disregard for basic human and industrial rights, either here or in Pakistan," Unions NSW secretary Mark Lennon said in a statement.

Employees at the factory earn less than $3.50 a day - one third the wage of permanent workers - and have no annual or medical leave, he said.

International Union of Foodworkers regional secretary Ma Wei Pin says some workers had suffered injustices under the system for more than 20 years.

"More than 90 per cent of these workers are on a `no work, no pay' system. They arrive each day at the factory and are assigned work. If they are not given work they must go home and are not paid," she said.

Unilever says it has a Code of Business Principles that clearly states that it is the company's goal to conduct its operations with respect for the rights and interests of its employees.

In a statement, the company said it was in discussions with the International Union of Food, Agricultural, Hotel, Restaurant, Catering, Tobacco and Allied Workers' Association to review the use of temporary labour at its factory.

"Unilever Pakistan is committed to mutually resolve the issue in coordination with IUF and workers' representatives for the long-term benefit of all," it said.

Unions NSW was planning mass meetings of Unilever workers at all of the company's NSW workplaces, Mr Lennon said.

"This is a basic issue of dignity at work and we will stand with our Pakistani brothers and sisters to ensure they get justice," he said.