The agreement was reached as the two sides met at the Fair Work Commission in Canberra to hear an attempt by the giant Department of Human Services to have the strikes by workers at Centrelink, Medicare and the Child Support Agency ruled illegal.

The department says the planned strike was at least in part a protest against the policies that have led to the ongoing "robo-debt" debacle, which would make the action illegal under the Fair Work Act.

The Community and Public Sector Union rejected the DHS position, saying it was "ridiculous" and that the actions were all about the bitter dispute over conditions and pay that has raged between DHS and its 34,000 workers for three years.

But it is understood the department withdrew its FWC application on Friday morning, without the commission making any orders, in return for the union agreeing not to go ahead with the strike action.

The two sides have agreed to hold more talks.

CPSU National Secretary Nadine Flood said both parties reserved their rights if the discussions are not productive and that this could include further strike action.

"CPSU has already sought the Commission's assistance in this ongoing dispute, including in good faith bargaining applications in this and other agencies, so of course we're open to pursuing this further," the union leader said.

"We're always willing to talk but after waiting three years for a resolution of this protracted dispute, the CPSU reserves our right to take further protected industrial action or other steps as required."

Human Services has been approached for comment.