Industrial action at the Australian Tax Office looms larger as 20,000 staff have been told they will not receive a pay offer this year and one union is calling for a work-to-rule campaign that could cost the federal government billions of dollars.
Two major unions will need to put aside a longstanding rivalry for it to happen and one expert has warned about the dangers of industrial action by bureaucrats who did not seem to have much support across Australia.
The larger Community and Public Sector Union was not ruling in or out industrial action at the Tax Office as it slammed the lack of a pay offer before Christmas as a "searing indictment on the unworkable nature of the Abbott government's bargaining rules".
"Clearly the Tax Office has a key role to play in helping plug the government's revenue shortfall so having a cloud of uncertainty hanging over tax workers for longer is not going to help," CPSU deputy national president Alistair Waters said.
"We are committed to finding a way to a reasonable and sensible outcome but in a year not a single agreement has been reached and public servants are clearly losing their patience."
Australian Services Union official Jeff Lapidos went a step further by saying he will encourage staff to support a work-to-rule campaign in 2015 which could cost the federal government billions of dollars.
"We need to hurt the government financially far more than they're hurting us," Mr Lapidos said.
"I'm expecting we'll ask members to do the minimum required when it comes to assessing people's liability to pay tax."
Mr Lapidos said the impact on revenue would need to be more than the estimated $60 million he said it would cost for an annual pay rise of 4 per cent but he conceded he would need the CPSU to agree with his strategy for it to work.
About 30 per cent of the ATO's workforce are CPSU members while the ASU has up to 1000.
The ASU-CPSU turf war erupted during ATO bargaining in 2010 when the two disagreed over a pay offer and the ASU criticised the CPSU in the press over its united pay deal strategy.
"I'd certainly be trying to encourage the CPSU to have something consistent to what we're putting in place," Mr Lapidos said on Wednesday.
Former tax official and Taxpayers Australia spokesman Mark Chapman said industrial action could have a "severe, immediate" impact on revenue collection.
"A number of (executive level) staff work beyond the standard hours," Mr Chapman said.
"And taking industrial action around tax time would be far more serious."
He said the Tax Office was already stretched because 3000 jobs were cut by October 31.
University of Canberra industrial relations expert Phil Lewis said there seemed to be little public support for bureaucrats taking industrial action compared with Australian Defence Force members whose below-inflation pay deal was met with more widespread outrage.
"There's a mindset that Canberra and the public service has done pretty well," Professor Lewis said.
"They've got to be careful the way they play this one - the consequences for the public sector unions could be quite dire."
Professor Lewis said more complex tax collection - which involved companies and businesses - would be scrutinised less during industrial action.
The ATO would not comment because it said it was bargaining in good faith.
Any industrial action will need Fair Work Commission approval. CPSU union members at the Department of Human Services and Department of Veterans Affairs are taking part in a ballot to gauge support for industrial action.