Moray Council held “secret talks” with military chiefs about the closure of the Kinloss Barracks – four months ago.
It emerged yesterday that senior local authority officials and discussed the potential axing of the base with the Defence Infrastructure Organisation (DIO).
It is heading the review which could lead to the barracks being shut – five years after the demise of Kinloss as an RAF station.
The Ministry of Defence (MoD) has insisted no decision had been made on the future of the barracks but campaigners are already laying plans to battle to keep them open.
Kinloss is home to 39 Engineer Regiment and employs more than 700 service personnel and pumps £30million into the local economy every year.
Moray MP Angus Robertson accused council chiefs of failing to challenge the MoD over “broken promises” to the region.
But the leader of the local authority said that the DIO insisted the conversations remain confidential.
The Army moved on to the site in 2012, following the controversial decision to close RAF Kinloss the previous year.
Moving 39 Engineer Regiment to the region was designed as a way of plugging the gap in the region’s economy.
In July 2011, then-defence secretary Liam Fox said the site’s rebirth as an Army barracks would “provide this part of the country with a good long-term future”.
Mr Robertson said it appeared the council was allowing the UK Government to “abandon promises” made to Moray in the wake of the closure of RAF Kinloss.
He added: “The emerging details of the threat to the Kinloss Army base show that the council, which is run by a Tory and Independent-led administration group, has been having discussions with the MoD over the future of the base.
“They have chosen not to publicly challenge the government on the promises made to Moray.
“The Tories have made promises to Moray – at UK Government level and at council level in Moray, there has to be accountability for those promises.
“Many service personnel and their families have made their home in Moray, and our local communities are hugely supportive of the bases.
“To close Kinloss Barracks and reduce the defence footprint even further in Scotland would be totally unacceptable.”
Council leader Stewart Cree said DIO chiefs had sworn the officers involved to secrecy, and insisted he was only made aware of the base being in jeopardy on Monday.
Mr Cree, who is an Independent councillor and heads the administration alongside Conservative convener Allan Wright, denied that any “collusion” had taken place.
He said: “Our senior officers have ongoing discussions with the DIO as a matter of business.
“They were on pain of death not to mention anything about this, because there could be commercial interests involved – that was how the DIO wanted to play it.
“I can put my hand on my heart and say I knew nothing about any of this.
“We have not been acting in collusion, anyone who was part of any proposal to close the barracks was required to keep that confidential.”
A council spokesman added: “Senior officers have had discussions with DIO representatives as part of the MoD’s footprint review.
“Given its close association with the military bases in its area, the council is frequently involved in discussions on a wide range of issues of common interest and by their nature these discussions are generally informal and confidential.”
The Ministry of Defence refused to comment on the discussions with the council.