Sea King helicopters are coming to the end of their working life
The Ministry of Defence (MoD) says it will not be able to reverse a decision to move search and rescue services from Prestwick to Glasgow Airport.
It follows a decision by UK ministers to transfer Britain's search and rescue services (SAR) to a private consortium.
There are claims the move threatens the future of the Prestwick naval base HMS Gannet as most of its work is search and rescue.
Local politicians have described the decision as "an absolute outrage".
The new service will combine the current work of the RAF, navy and coastguard.
The MoD said that under the terms of the multi-billion pound deal, it would be up to the new operator, Soteria, to decide where to base its rescue helicopter services.
The consortium - which includes includes Royal Bank of Scotland - will begin to take over SAR from 2012.
The new deal will mean there are likely to be fewer helicopters, reduced from the current 38 around the UK, to possibly as few as 24.
However, ministers argue that newer faster and larger Sikorskys will replace the ageing Sea Kings and will provide a better service.
Defence Minister Quentin Davies told BBC Scotland that under the £6bn deal, helicopters will not fly from the Prestwick base but will instead fly from Glasgow Airport.
The decision has brought a furious response from local MPs.
Ayrshire Central Labour MP Brian Donohoe said he would fight the move which would affect more than 100 crew and other staff based at Prestwick.
Mr Donohoe said he was assured by a government minister that Gannet was safe, before learning that operations are to be moved to Glasgow.
"I'm speechless. The reasons for moving search and rescue from Gannet are completely flawed," he said.
"It will mean the end of Gannet because search and rescue is 90% of what it does.
"It beggars belief. I was told that Gannet was safe. I'm beside myself with rage.
"The decision's been taken without even involving the local MP despite me being assured by the former defence secretary that this was all sorted and Prestwick was fine."
John Scott, Conservative MSP for Ayr, said: "I find it hard to believe that it is a better deal for the taxpayer. This is a bombshell for our area. There is absolute outrage. There has been absolutely no consultation about this whatsoever.
"These will be 100 high quality jobs taken out of the Prestwick area and there is absolutely no need for this at all.
"Prestwick Airport is a state-of-the-art facility at HMS Gannet and to move these jobs essentially 30 miles up the road? It seems like some sort of political fix has been done here.
"I think this is the wrong decision and I'll certainly be lobbying to get it changed. I will be making every endeavour to see if this decision can be overturned even at this late stage."
Westminster SNP leader Angus Robertson MP, who represents Moray, said: "I have always been sceptical of Labour's plan to privatise all search and rescue cover.
"With a lack of transparency about the detailed PFI plans we need an assurance that no deal will be signed off until after the forthcoming UK general election.
"Questions also remain unanswered about the long-range rescue cover usually provided by the RAF Nimrod fleet.
"With only weeks to go until the MR2 Nimrod aircraft are taken out of service there is still no confirmation how their vital role will be continued during the gap period before the delayed replacement MRA4 aircraft come into service."
A Ministry of Defence spokeswoman said: "As part of the invitation to tender for the SAR-H contract it was decided that as Prestwick airport is a commercial airfield the preferred bidder could retain the SAR service at this site or relocate it to a nearby airfield as long as the terms and conditions of providing the SAR service in this region remain unaffected.
"Soteria Consortium in their bid had made it clear that they would move the SAR service, currently provided by HMS Gannet, from Prestwick airport to Glasgow airport.
"This decision was taken by Soteria for purely commercial reasons.
"HMS Gannet, as a Royal Naval Air Station, has a wider military role and its future is not directly related to the SAR-H decision. However, all aspects of defence will be under scrutiny in the forthcoming Strategic Defence Review."