The Community and Public Sector Union (CPSU) plans to ask Prime Minister Kevin Rudd for 26 weeks paid maternity leave for Commonwealth public servants within the next five years, reports the ABC.
Most federal public servants are currently entitled to 12 weeks paid maternity leave, with some getting 14 weeks.
CPSU national secretary Stephen Jones says the make-up of the public sector is changing and workplace conditions should reflect that.
"It's over 30 years since the paid maternity leave legislation introduced 12 weeks paid maternity leave for Commonwealth Government employees and we think its time to review that," he said.
"It's really time to shift the goalposts significantly beyond and we think that 26 weeks paid maternity leave is the proper standard."
Mr Jones says the Federal Government has the opportunity to become a model employer.
"Whether viewed from the interests of the child, the mother or the workplace we think that's about where things should be in today's society," he said.
A spokeswoman for Acting Prime Minister Julia Gillard says the Federal Government is open to considering the idea as part of the bargaining process.