It's the latest strike in a troubled few months for the parcel delivery industry, which has seen companies and workers standing off over work conditions and outsourcing.

The Transport Workers' Union says FedEx workers had successfully won job security protections in negotiations, but that the company was now trying to drag down other standards.

The FedEx staffers had originally planned to walk off the job on Thursday but called it off to allow for further negotiations.

A 24-hour strike is now slated to take place on Monday.

It comes after StarTrack workers went on strike on Thursday - for the second time in a month.

Australians are already facing longer than usual wait times for deliveries, with the sector buckling under the pressure caused by a spike in online shopping amid months of lockdown.

A FedEx spokeswoman said the company was concerned the strike could not come at a worse time for Australian businesses coming out of lockdown, and that it would adversely impact customers and the community.

The company is cooperatively negotiating with the TWU and wants to reach an agreement as early as possible, she said.

The spokeswoman says the company has addressed the union's primary concern of job security and, where feasible, has made concessions to resolve approximately 90 per cent of the union's claims.

TWU National Secretary Michael Kaine is accusing FedEx of importing an American-style anti-worker campaign into Australia.

He said FedEx workers were angry their good will had been "thrown back in their face" this week.

"It is a disgrace that FedEx took the extra time agreed to by workers to change tack and launch a fresh assault on their terms and conditions," Mr Kaine said.

"These workers generated record multibillion-dollar profits for FedEx but their pay and conditions fall dangerously below those at their competitors like Toll and Linfox."

An industry-wide strike planned for this week was avoided after deals were reached at Toll, Linfox, Global Express and BevChain.

Australian Associated Press