Upcoming strikes by Border Force officials and other public servants have been condemned as "unfortunate, ill-conceived" and "counterproductive" by Employment Minister Michaelia Cash.
Senator Cash, who also holds the public service portfolio, says plans for ABF and other Immigration Department officials to walk off the job for 24 hours on Easter Thursday have the potential to hurt the travelling public.
The 24-hour strike, part of a continuing dispute over wages and conditions, will be preceded by strikes by public servants at the Tax Office, Medicare, Centrelink, the Child Support Agency and the Bureau of Meteorology.
But the planned action may not go ahead if Immigration bosses achieve a hoped-for yes-vote in the ballot of the department's 13,500 public servants currently underway. The last ballot, in September 2015, ended in a crushing no-vote.
An Immigration spokeswoman said on Wednesday that the main workplace union had not yet lodged the necessary paperwork with the Fair Work Commission to secure legal protection for its planned Easter action.
Bureaucrats at the Department of the Prime Minister and Cabinet and the Bureau of Statistics are also planning to join in the 24-hour strike on Monday, March 21, in what will be the most comprehensive industrial action seen so far in the dispute.
The Community and Public Sector Union, representing the Border Force officials and other public servants, says the action could escalate further with a three-week campaign of rolling airport strikes over the Easter school holidays being considered.
Unions and Labor seized on a narrow rejection on Wednesday of a wage proposal at the giant Defence Department to call for the government's bargaining stance to be dropped, but the Employment Minister was unwavering.
Senator Cash condemned the planned strikes, telling Fairfax the union was taking the wrong approach to workplace bargaining.
"It is unfortunate that the CPSU resorts to strike action," the minister said.
"This can cause harm to the public and involves a loss of pay for employees.
"There are more constructive ways to undertake workplace bargaining.
"Instead of resorting to industrial action, the CPSU would better serve the interests of their members if they were to genuinely negotiate in good faith.
"If the CPSU's plan is to further inconvenience and disrupt the Australian public over Easter, I believe their strategy is ill-conceived and counterproductive."
An Immigration Department spokeswoman said it had not yet been officially notified of the planned strike action.
"The Community and Public Sector Union has not notified the Department of any plans to take protected industrial action," she said.
"A ballot is currently underway for staff to vote on a proposed enterprise agreement.
"This ballot is open until Sunday."
Meantime, Labor has announced that Senator Cash has a new opposite number with ALP employment spokesman taking over from the retiring Gary Grey as the party's public service shadow minister.
"I am taking on this added role at a time when the government's attack on the public service has led to a workplace bargaining impasse, and Labor will continue our defence of these worker," Mr O'Connor said.