The RAF is to move 340 military posts from Lossiemouth and shed 50 civilian jobs as part of the Ministry of Defence armed forces review.
Maintenance posts at RAF Lossiemouth are to be moved
The affected posts are in engineering and the maintenance of Tornado aircraft at the Moray base.
It comes just 24 hours after a lobby group met defence ministers to argue the case for keeping Moray's two centres at Lossiemouth and Kinloss.
There are fears about the impact of the cuts on the local economy.
The service posts will be redeployed to RAF Marham in Norfolk and the civilian jobs will go over the next four years.
The MoD is examining RAF bases as part of its spending review with RAF Lossiemouth and Kinloss earmarked for cuts.
Between them, they employ nearly 5,000 people and inject almost £100m into the Scottish economy.
Lossiemouth is the RAF's largest and busiest fast jets base.
It is home to three operational squadrons of Tornado GR4s, the Tornado GR4 Operational Conversion Unit, a Sea King Search and Rescue Flight, an RAF Regiment Field Squadron and an RAF Regiment Auxiliary Squadron.
About 2,500 military and civilian personnel work at the base, which was built during 1938 and 1939.
Enterprise company officials expressed fears for the Moray economy when they met government representatives on Tuesday.
Confirming the changes, which are due to begin next year, Armed Forces Minister Adam Ingram said the plan was his "preferred option" although a consultation with trade unions was under way.
Asked about accusations that it might be the start of a run-down of the base, an MoD spokeswoman said: "At the moment we are in the middle of completing a defence airfield review and it is too early to speculate on the outcome of that.
"There is no way we can rule in or rule out any of our airfields at the moment.
"We need to make ourselves into a leaner air force and that can be done by reducing the number of airfields we maintain."
Acting Station Commander Wing Commander Al Monkman said: "We have a duty to be prudent with the taxpayers' money.
"The announcement today enables us to operate best-practice and get value for money out of our engineering and logistics procedures. So this is good news."
The SNP MP for Moray, Angus Robertson, said: "This is yet another attack on Scotland's defence, at a time when our forces personnel are more stretched than ever.
"In a matter of weeks the MoD has announced the disbandment and amalgamation
of regiments that, as we speak, are involved in combat situations around the
world, a review of RAF bases that threatens the existence of RAF Lossiemouth and
RAF Kinloss and now this announcement of 390 high skill job losses in Moray.
"The lie is being exposed of London government support for defence in
"Our service personnel are devalued, our support industries decommissioned
and our communities destroyed.
"This latest announcement should serve as a salutary warning for those who doubt the risks of Scotland's defence policy being made in London and will galvanise the campaign to save defence jobs, units and facilities all over Scotland."