The East of England Ambulance Service, criticised over poor response times, is to take delivery of 120 new vehicles.
The first will go into service in Norfolk, where cover has been described as poor by health watchdogs.
The aim is to have no ambulances over five years old.
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It will stay cold this afternoon with an increased risk of sleet and snow showers, especially in the north and west.
The Met Office has issued at yellow "be aware" warning for snow and ice in the Anglia region for Thursday evening into Friday.
Police have discovered a cannabis factory in a mansion at March in Cambridegshire