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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Warm sunny spells today remaining dry
Remaining dry with warm sunny spells on Monday.
Douglas Carswell told ITV's Peston On Sunday he wanted to "support" the government as a "critical friend" but refused to rule out a return.