Australia Post says it has temporarily withdrawn its entire fleet of 1,111 high-capacity, electric delivery vehicles or eDVs "due to safety concerns with the front axle of the vehicle".

The Communications, Electrical and Plumbing Union of Australia said the axle holding the front wheel of the vehicle collapsed on three eDVs operating from Ingleburn last week.

Around 320 of the three-wheelers were in use across the country when Australia Post called for the vehicles to be withdrawn on Monday. Up to 129 vehicles were in use across the Newcastle and Hunter region on any given day.

A spokesperson for Australia Post said it was working with the manufacturer to ensure the axle issue was addressed and using alternate methods of delivery so services would not be affected.

"The safety of our people is paramount, importantly no one was injured due to the axle issue, and we will only commence delivery with these vehicles once the manufacturer can confirm all axle issues are addressed and the vehicle is safe for riding," he said.

"To ensure all mail is delivered we're streaming more parcels to our delivery drivers, our posties are using motorcycles and our fleet of Electric Assisted Mail Bicycles to deliver their rounds, and we've even got posties on foot in some areas."

Newcastle was the second city in Australia to trial the electric-powered, high-capacity three-wheeled vehicles during a test-run in late 2017.

The Newcastle Herald understands that since the trial, Australia Post has rolled out the vehicles to other delivery centres across the country including Ingleburn, Frenchs Forest, and Seven Hills in NSW.

Shane Murphy, the state secretary of the CEPU, said he was glad Australia Post had made the "right choice" to stop using the vehicles until their safety was assured.

"The union advised Australia post that if they did not put that in place we would have been instructing riders to not ride those vehicles," he said.

"Our members will continue to support Australia Post's delivery of items leading up to Christmas."

Mr Murphy said Australia Post had agreed to engage an independent assessor to test the road-worthiness and safety of the entire vehicle before they were put back on the road.

"There has been variable issues with the vehicle since their introduction and the union hasn't always been satisfied with the response to concerns," he said. "However, we've go to the point where both Australia Post and the union are ensuring our members safety comes first prior to their re-introduction."

He said he also appreciated Australia Post's efforts to find new ways of handling and delivering mail.

"We will work through those changes to ensure postal workers continue delivering to the communities they have been serving for such a long time," he said.

Last year, the Newcastle Herald reported four delivery drivers had been injured on their rounds in the vehicle to the extent they had to spend time away from their normal duties.

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