The Community and Public Sector Union has suffered a big tactical loss in its highest profile industrial action campaign within the Australian Public Service, after the Fair Work Commission banned further strikes at the Department of Immigration and Border Protection, including Border Force, for 90 days on national security grounds.

Fair Work on Wednesday issued an interim decision that suspends protected industrial action at DIBP for 90 days after the department took its case to the industrial umpire complaining that national security arrangements could be compromised or diminished because of union strikes and bans.

Until now airport strikes had been one of the most potent weapons in the CPSU’s dispute arsenal because of their high public profile and impact which demonstrated that those at the coalface of national security have been offered such a dud workplace deal they were left with no option but to strike.

The CPSU throughout its campaign has insisted that the strikes and bans imposed by its members do not compromise security arrangements but rather just slow down processing and screening, sometimes by applying more of it.

However the union’s argument has been hit for six by Commissioner Nick Wilson who found that the CPSU’s evidence “did not persuasively address the matter of how the design and delivery of the protected industrial action impacted upon the ABF’s [Australian Border Force] risk profile.”

[Read the full decision here]

The core of the decision – which will likely be appealed by the CPSU – appears to be a rejection of the argument that operations at the border can be disrupted without hitting risk profiles, especially if the CPSU escalation tactics were aimed at countering the effectiveness of so-called “surge staff” deployed by DIPB and Border Force to counteract the impact of legal walk-offs.

“The evidence compellingly illustrates a highly sophisticated plan for industrial action in which staff may be withdrawn at many locations, for many hours of the day. A consideration for when there were to be walk-offs was the level of impact it would have at that time,” Commissioner Wilson found.

“It also compellingly shows that the intention of the action was to wear down the capacity of the ABF to avoid the action through deployment of surge staff, for reason of the action being sustained for an ongoing period. Without question, the evidence shows the protected industrial action to have had a suffocating effect. The capacity of the ABF to undertake its core functions was seriously affected,” Commissioner Wilson said.

The Fair Work decision is a real problem for the CPSU at DIPB and Border Force because it effectively draws a line under the union’s ability to gradually ratchet up its campaign of stoppages.

Importantly, Fair Work found that the longer that protected stoppages went for, the more the risk of compromised national security was aggravated.

“It becomes foreseeable that criminal or terrorist opportunistic behaviours become more likely as a result, since systemic weaknesses can be more easily identified and exploited. The evidence shows this risk is not merely foreseeable, but that such behaviour more than likely occurred within the recent period of protected industrial action,” Commissioner Wilson wrote.

Although a clear tactical win for the Department of Immigration and Border Protection, the latest Fair Work decision doesn’t itself get to the crux of the dispute between CPSU members and their employer that hinges on the dilution and removal of workplace conditions and departmental restructuring that could cost former Customs staff as much as $8000 in take home pay a year.

The already bad blood between the CPSU and DIPB’s senior management is also likely to be exacerbated after the union yielded to a request from the government via Prime Minister Malcolm Turnbull to voluntarily halt strikes it had previously planned that would have taken place in the immediate aftermath of the Brussels airport terror attacks.

On Thursday there were already back room rumblings that the government will now increasingly seeking to exploit fears over national security and portray union members as militant hot heads that put their own pay ahead of the safety of others.

There are also rumours that the airports dispute and Fair Work’s findings will be used in anti-union online ‘attack ads’ after the Turnbull government declares an election date.

Despite copping a legal bruiser, the CPSU isn’t backing down and greeted the Fair Work decision and order with “extreme disappointment”.

“We’re disappointed with this decision but not surprised by it, given the inherent seriousness of matters related to national security and counter terrorism,” said CPSU National Secretary Nadine Flood.

“We are carefully examining the full ruling and taking legal advice to consider whether there may be grounds for an appeal, given the significant inaccuracies in the Commonwealth’s case.”

“We agree our members’ industrial action was designed to have a significant impact on the Border Force and the Government, but categorically reject that this action would have posed a risk to the Australian community,” Ms Flood said.

“We absolutely reject any suggestion that the CPSU or our members in Border Force have done or ever would do anything other than act lawfully and responsibly to fight for their rights, conditions and take-home pay.”

The CPSU immediately hit back at Commissioner Wilson’s decision, saying it contained “significant errors in key planks” and similarly blasted DIPB’s evidence as containing “significant inaccuracies.”

The CPSU said that assertions in evidence of an increased risk to national security had been contradicted by when “Border Force said something different to their own staff in writing” – a fact it says Fair Work ignored.

“We will have more to say in coming days and are looking forward to being able to expose the serious issues raised by the conduct of the Department of Immigration and Border Protection and the Australian Border Force in this case,” Ms Flood said.

In the meantime, politicians preparing to go into an election campaign after next week’s Budget can fly safe in the knowledge they won’t be hit by strikes at the nation’s airports.