The extent of the cuts will depend on government grant funding formula, which affects how much money the service will receive.
Earlier this year CFRS announced up to £6 million worth of cuts, including the proposed closure of Manea Fire Station and changes to the way both March and Wisbech Fire Stations are run.
However, at least £1 million of those saving will not be necessary if the government’s funding formula remains unchanged.
Possible population growth and inflation could also have an effect and the situation is expected to be clearer by the end of November when the government completes its spending review.
At a press briefing on Thursday, ahead of this Thursday’s (October 13) Fire Authority meeting, Chris Strickland, Deputy Chief Fire Officer, explained: “At the moment we don’t know if we need to make £4.2 million or closer to £6 million worth of cuts.
“We have already identified how we can save £4.2 million and this was approved by the Fire Authority in May. We are confident those decisions will not affect the level of service provided by CFRS to members of the public and we are now in the process of delivering these savings which has given us some breathing space.
“However, as we have always said, if the figure is nearer £6 million, the Fire Authority will have to make some difficult decisions. Decisions that will impact on the public.”
But he added: “We believe it’s only right that we make key decisions which impact on the level of service to the public when we have an accurate picture of the financial situation, and not before.”
Up to 40 non-operational staff jobs will be lost as a result of the support service cuts of £2.6 million, and 25 firefighter jobs will go if the service changes to a new shift pattern, saving £900,000.
Unions have welcomed the decision to defer decisions on the front line cuts, but expressed concern at the loss of firefighters.
The support jobs will be lost from back-office functions across the county, and will include some compulsory redundancies, while the firefighter jobs will hopefully be reduced through natural wastage.
The Fire Authority will receive updates on feasability studies announced earlier this year by CFRS.
The proposal to convert March to nucleus crewing is not recommended to be pursued at this time.
A study looking at the service’s three day crewed stations, including Wisbech, took in various options ranging from moving Wisbech to five-day crewed to converting all three stations to retained status.
But while changes would release around £1 million of savings the impact on public safety would be significant and so the service has asked the Fire Authority to defer a decision until February.
Decisions on the closure of Manea fire station, and five other retained appliances have previously been deferred to May 2012.
Mr Strickland also said the service would continue working with other services to save money and improve efficiency.
The Fire Authority will discuss the CFRS recommendations at Thursday’s meeting.