St John says it anticipates pulling some ambulances off the road when staff are sick or on leave will continue until the start of winter.

It's limiting calling in extra staff to save money.

Ambulance Services Deputy Chief Executive Dan Ohs says they expect the workload to rise from late May.

"Doing this now enables us to make sure we've got the financial depth in order to ensure we can stand additional resources up for winter."

LISTEN ABOVE