Thousands more parcel delivery workers are walking off the job today, with FedEx workers joining the fight for job security.

Up to 3000 workers have walked off the job for 24 hours.

The Transport Workers Union says the company has refused to offer guarantees for positions despite generating a net record profit last year.

Thousands of StarTrack employees went on strike last week to stop the outsourcing of work to contractors.

Victorians are already facing longer than usual wait times for deliveries with more people than ever shopping online.

Meanwhile, Australia Post will halt eParcel and Parcel Post pickups, collections and lodgements from eCommerce retailers in the Greater Melbourne area for five days, beginning Friday.