The CSPU says the reported remarks from Treasurer Joe Hockey, that 3000 jobs will go in coming months, would be the best news that tax avoiders would hear all year.

The Australian Services Union also reacted with dismay to that more tax workers would lose their jobs, saying the move will make it harder for the ATO to collect much-needed revenue.

CPSU National Secretary Nadine Flood described the report as “gut wrenching” and predicted tough times for those left behind.

“This report is gut-wrenching for workers at the Taxation Office who are already struggling under the pressure of earlier cuts,” Ms Flood said.

“Joe Hockey has been telling every man and his dog that revenue is not keeping up with spending, but now it’s reported he wants to cut 3000 revenue collection staff.

“If that’s the case, it’s crazy.

“Slashing 3000 tax office jobs will be the best news tax avoiders and other shonks will hear all year.”

The ASU’s tax office organiser Jeff Lapidos says the job cuts would hurt the ability of the ATO to collect revenue for the government.

“The 3000 reduction in staffing numbers will come as a shock to ATO Employees generally,” the union official said.

“If this report…is confirmed in next Tuesday’s Budget, the people of Australia will find the ATO’s ability to collect the revenue for Government will be significantly compromised and its service standards will fall.”

ATO bosses themselves said they had no information to offer their workers on Friday morning after the Treasurer said 3000 of them were to lose their jobs.

Responding to reports that up to 13 per cent of the office's staff would be culled in the coming months, the ATO's 23,000 employees were told that they must wait four days to learn their probable fate.

Second Commissioner Geoff Leeper told his staff they would have to wait four days for details of the reported job cuts.

"You would have seen media coverage this morning regarding proposed staffing reductions across the APS," Mr Leeper wrote.

"We will need to wait until the Federal Budget is released on Tuesday for details of these and any other outcomes for the ATO.

"Following the Budget release next week we will be communicating with you further on what it means for us."

The reported job cuts come on top of the slashing of 900 ATO positions this year, 500 to 600 through voluntary redundancies.