Plans to close Fort George as an active Army barracks are expected to be confirmed this morning.
The Ministry of Defence is poised to set out proposals to give the base at least a 10-year stay of execution.
But the move will signal the beginning of the end for the Army’s near-250-year presence at the fort.
Last night, there was growing anger in the north over the controversial move.
Campaigners have been battling to save Fort George after fears over its future surfaced in the summer.
Highland MP Drew Hendry described the possible pull-out of the military as a “devastating blow” for the region – and warned the decision would not be accepted by communities.
The MoD remained silent on the future of Fort George yesterday, but several sources confirmed an announcement would be made this morning.
It is also expected there will be no impact on Kinloss Barracks in Moray, which had been rumoured to be under consideration for closure as part of the current defence review.
It is anticipated that Fort George will be retained for at least the next 10 years before the 500-strong Black Watch 3 Scots battalion currently based at the barracks is moved to another base in Scotland.
The pull-out will be a huge blow to the economy of the Highlands and particularly Inverness, where many of the Black soldiers and their families live.
The Press and Journal has campaigned against any closure of Fort George, with thousands of people signing a petition calling for it to be retained, including Hollywood actor Hugh Grant, who has personal connections with the base.
SNP MP Mr Hendry has been heavily involved in the campaign and reacted with fury last night.
He said: “If these rumours are true, it is a devastating blow to the communities in my constituency, that have a long and proud history of serving the military.
“For months, I have asked the UK Government to share with us what their plans are for Fort George, yet the silence has been deafening.
“If this has, as I long suspected, in fact, been an attempt from this government to avoid hearing our case for Fort George, then it is completely disrespectful to my constituents.
“The Scottish Government has already been locked out of this entire process, and the secretary of state for Scotland has been actively briefing against Fort George.
“It is completely unacceptable and I will be demanding immediate answers.
“There is no way any attempt to close – or commence a rundown of this historic base – will simply be accepted by our communities.
“I will continue to press the UK Government to live up to its responsibilities to the area, the families who would be affected and to the historic Black Watch.”
Highlands and Islands Conservative MSP Edward Mountain, a former major who served for 12 years with the Blues and Royals cavalry regiment, responded to the news last night.
He said he would welcome Fort George staying open for at least the next 10 years.
But said that from a military point of view “it probably doesn’t justify being kept open as a barracks”.
He added: “The barracks are a listed building and you can’t give soldiers proper accommodation there.
“At Fort George, we’re so far away from training areas that for the regiment to use their Foxhound vehicles they have to go down to Otterburn (Northumberland).
“To use the weapons systems they have, they can’t fire them and they have to go down to Dundee.
“As a father of a soldier, and an ex-soldier, I’d rather time that my son had was spent training rather than travelling on buses.”
He added that because the regiment recruited from across the country, having soldiers based in Inverness often meant separating them from their families who live elsewhere in Scotland.
Defence Secretary Michael Fallon said on Friday he would make an announcement “very shortly” and refused to rule out mothballing Fort George.
The fort was built after the Battle of Culloden and as well as being an active barracks also acts as a tourist attraction, being home to the Highlanders’ Museum.