The giant Department of Human Services wants to cut the pay and conditions of nearly 1800 casuals who answer phones at Centrelink, Medicare and Child Support Agency call centres around the country, according to the main public sector union.

The CPSU says DHS bosses want to cut the hourly rate paid to the workers, most of who are women living in regional Australia, as well as slashing their weekend loading by 28 per cent and shutting off any hope of them securing permanent jobs with the department.

But Human Services told The Canberra Times on Wednesday that it had not yet finalised its new offer for the 1780 casuals.

The fate of the casuals is the latest battle to break out between the department and unions as DHS, the government’s largest department, tries to strike a new deal on pay and conditions with its 30,000 workers.

Late last month, the department’s management abandoned plans for a snap ballot of its workers, that would have bypassed unions, on a pay deal worth about 0.8 per cent per year, after running into stiff opposition at it workplaces.

The looming industrial struggle at DHS is being closely observed across the Australian Public Service with Human Services still the only department to have put a firm pay offer on the table.

The casuals typically earn about $28 per hour with a 20 per cent casual loading, but the CPSU, in a bulletin to members, says DHS negotiators have floated the idea of a 1.3 per cent cut to those wages.

The workers are mostly called into work on an “as needs” basis to call centres in Brisbane, Toowomba, Newcastle, Coffs Harbour, Wollongong and Tweed Heads.

Traralgon in regional Victoria hosts the largest Commonwealth call centre with 280 casuals, half the workforce, on its books.

The union says DHS is planning to cut off any prospect of a pay rise for the casuals, 70 per cent of whom are women, scrap performance bonuses, cut their pay, and cut their loading for working weekends by 28 per cent.

A Human Services spokeswoman would not confirm the union’s position on Wednesday.

But the CPSU’s National Secretary Nadine Flood was on the offensive on Wednesday saying the proposed treatment of the casuals was “mean and nasty”.

“These workers have no fixed hours, no leave and no sick pay,” Ms Flood said.

“They can be told half an hour before a shift starts that they are no longer needed and now this government wants to make their life harder.

“It’s what we have come to expect from a mean and nasty government that is taking it out on lower-paid workers.”

The DHS spokeswoman said that proposed pay rates for casual staff were being reviewed and could not be supplied for this article.

“The proposed new draft Enterprise Agreement is currently being reviewed and will also include relevant pay rates,” she said.

“We remain committed to working towards an agreement we can put to a staff vote as soon as possible, and will continue to negotiate with all union and non-union representatives in good faith.”