Is it a pay rise, or a pay cut? Whatever it is, it’s complicated.

Just hours after the massive Department of Human Services thumped its latest pay offer to staff onto the industrial bargaining table, the Community and Public Sector Union (CPSU) has ripped into the proposed deal, branding it a pay cut in disguise thanks to a slew of chopped back conditions and entitlements.

Chief among sticking points is the department’s insistence on keeping an increase in working hours in the bargaining mix to help achieve a peppercorn pay increase that is well below inflation.

Human Services on Tuesday offered around 35,000 staff an increase of 4.15 per cent over the three-year span of the proposed new enterprise agreement consisting of 1.5 per cent for 2015, 1.5 per cent for 2016 and then 1.15 per cent for 2017.

But a key part of the offer hinges on an increase in working hours of six minutes a day. The CPSU reckons that adds up to nearly a week’s extra work a year at 4.5 days and is a total dud.

And there are duds everywhere. The giant welfare agency is just one of dozens of government departments now grappling with the reality of applying so-called productivity offsets in the Australian Public Service Commission’s dogmatic bargaining framework.

The problem for the Abbott government — and subsequently senior APS management — is that attempting to redefine increased hours of work as boosting departmental output simply runs counter to the generally accepted definition of productivity; that is that more work or output is achieved in the same or a lesser amount of time.

The bifurcation of definitions has left government and department heads exposed to the logical and powerful counterclaim that compensating an increase in the length of a stipulated work day, without a corresponding increase in pay, is a real and tangible cut in the hourly rate of pay to staff.

According to the CPSU’s numbers, the impact of the extra hours gouges a 1.3 per cent cut out of the hourly rate paid to Human Services staff before inflation.

“Once again staff are being asked to accept a huge cut to their conditions and workplace rights in return for a pay offer that will see them go backwards over the next three years,” said CPSU Deputy National President Lisa Newman.

A major problem now emerging for the Abbott government is that the prosecution of the ‘hours as productivity’ argument across the public service’s enterprise bargaining round runs a real risk of spooking average Australians on hourly wages into a damaging cynicism that the real industrial relations agenda is to push down base pay rates by stealth.

There are other deal breakers too. The CPSU is similarly livid over conditions in the Human Services deal that make the agreement contingent on achieving ratios of middle management to non-executive staff of 1:9. The union argues this is simply out of the hands of its rank and file members.

“The offer goes from bad to worse if [Human Services] can’t sack enough people,” Ms Newman said.

“The ratio of staff to managers is something that’s entirely outside the control of your average Centrelink or Medicare worker and yet they are the ones who stand to lose if management fails to meet its target.”

In the event the management ratios are not achieved, the pay offer dives to just 3.25 per cent over three years.

But perhaps the biggest yet problem for Public Service Minister Senator Eric Abetz is there appears to be very little visible appetite among the CPSU and many public service staff to trade away conditions and entitlements.

The upshot of that equation means the Abbott government’s offers may well be stalled until a more flexible framework is found, either under this Parliament or the next.

On Tuesday, the CPSU conspicuously drew a line in the sand on the issue of preservation of conditions — as opposed to pay — before again unloading on Senator Abetz’s negotiating stance.

“Pay is an issue but it is not the most important one; staff are worried about their rights and conditions,” Ms Newman said.

“In light of this terrible offer, staff at Human Services are entirely justified in taking the industrial action planned for later this week. Minister Abetz needs to sit down and work through a path to sensible settlements if he is to avert more industrial action.

“If he doesn’t change his bargaining policy then he risks more public servants in joining the fray,” Ms Newman said.