Some Commonwealth departments and agencies are moving to top-up employees’ pay packets after the Federal Government softened is bargaining arrangements.

Late last year, public service minister Michaelia Cash gave up the hardline stance of her predecessor Eric Abetz, letting departmental negotiators offer pay rises of up to 2 per cent, rather than 1.5 per cent or less.

It means those departments that agreed to deals under the tougher bargaining arrangement became eligible to have their pay packets increased in line with the new offer.

This week, workers at Treasury, the APSC, and Social Services had their wages increased, despite some of their departments previously arguing that 1.5 per cent was all they could afford.

Social Services workers had voted for a pay rise of 4.1 per cent over three years, but will now get 5.8 per cent.

Treasury staffers will now receive the full offer of 2 per cent a year for three years.

A Communications Department representative has reportedly told Fairfax Media that the department had so far missed out on top-up payments.

“The current agreement provides for pay increases of 1.5 per cent in year two and 1 per cent in year three,” the spokesperson said.

“Following the change to the government's bargaining policy, there is scope for this pay offer to be increased, subject to affordability and consultation with the Workplace Consultative Committee and staff representatives.

“This process is ongoing.”

Senator Cash's own Employment Department is now being keenly watched.

The department is voting for a third time, this time on the enhanced offer, after rejecting pay offers by a landslide in December 2014 and by a fairly close margin a year later.