The postal workers’ union has called on Australia Post to offer retraining to any of the 900 workers whose jobs are reportedly on the line due to heavy losses.

The service’s 32,000 staff are expected to be told of the job cuts on Tuesday, Fairfax Media reports.

It says most of the jobs will go in Melbourne and Sydney, as Australia Post faces losses running into the billions if it continues to offer its failing letters business.

The service has already signalled that everyday home delivery of standard-priced mail could be cut back to two or three times a week, pending approval for government regulation changes.

The Communications, Electrical and Plumbing Union (CEPU) says reforms are unavoidable but the company is still turning a profit.

“It’s a terrible blow to lose jobs on this scale, but Australia Post is a big and evolving organisation and we’ll be making the case that new roles should be found for people who want to continue their service,” CEPU postal and telecommunications secretary Jim Metcher said on Sunday.

“The decline in volume of small letter delivery, Australia Post’s traditional service, does need to be addressed.

“But there is significant growth in new and emerging parts of the business, like parcel delivery.”

Comment from Australia Post has been sought.