Labor has flagged a move towards public service-wide bargaining and a reversal of the Coalition government's combative treatment of bureaucrats on pay and conditions.
The opposition has signalled to the Commonwealth's workforce of 150,000 bureaucrats it would not force agencies to cut staff rights and conditions, if it wins government.
However the Coalition said the opposition was misleading public servants, warning Labor's plan for service-wide negotiations would cause mess and delay, and take years to implement.
Labor's workplace relations spokesman Brendan O'Connor and shadow finance minister Jim Chalmers, who would oversee the reforms, said it would undertake genuine public service-wide negotiations on pay and common conditions, while agency-specific conditions would be negotiated at the agency level.
The main public service union has applauded Labor's promise, which included a vow to reverse the splintering of pay and conditions across agencies for bureaucrats that has occurred under recent Coalition and Labor administrations.
"Developing the first service-wide move towards fixing the Liberals' bargaining mess is a major undertaking that would first require some preparation time in government," Mr O'Connor and Dr Chalmers said.
"Prior to commencing service-wide bargaining, Labor would consider what interim arrangements may be required and how these would be taken into account in service-wide bargaining."
Mr O'Connor and Dr Chalmers said Labor would not use "industrial blackmail" or "draconian policy" to delay workers receiving a pay rise, in a jab at the long waits bureaucrats had for a wage increase while bargaining with the Coalition since 2013.
Finance Minister Mathias Cormann said unions rather than the Coalition's workplace bargaining policy had caused delays in pay rises. Public servants were agreeing to wage deals with minimal industrial action, he said.
"Labor know that service-wide bargaining would take years to land and the mess and delay their reckless agenda would cause gives them yet another reason to hold back pay rises as the unions have done too often in recent years," Senator Cormann said.
"For Labor to suggest that it would be desirable or that they could afford to pay public servants high wage rises at a time of low inflation, or be able to standardise hundreds of agreements in a timely way, is just not credible."
Labor has made the promises to public servants as it revealed its cost estimates for its headline reforms to the federal bureaucracy.
Its fiscal plan statement, released on Friday, estimated it would save $409 million next year through reduced spending on contractors, consultants and travel, a saving growing to $779 million by 2023.
A promise to hire another 1200 Human Services Department staff would cost $29 million next year and the bill would grow to $139 million in four years, according to its estimates.
Labor would also forego $136 million in scrapping the additional 0.5 per cent efficiency dividend - or annual agency budget cut - for the next financial year.
Its promises on public service wages and conditions follow a vow to lift the Coalition's cap on staffing levels, a restriction blamed for the government's growing spend on contractors and consultants.
"Labor is committed to building a public service that can properly deliver the essential government services our community relies on, offers frank and fearless advice to government, and has fair workplace conditions and rights," Mr O'Connor and Dr Chalmers said.
The Community and Public Sector Union, which has long fought against the Coalition's workplace bargaining rules for public servants, said Labor's workplace reforms would deliver the strong public sector required to deliver good government.
"Labor has pledged to take a vastly different approach to workplace relations for the Australian Public Service, undoing the harm caused to public sector workers and their families by the Abbott-Turnbull-Morrison government through a wage freeze of three years or more and large-scale cuts to working conditions, particularly family friendly conditions," the union said.
Public servants' annual wage rises are now capped at 2 per cent.