Military sites including the Faslane naval base are being put an “unacceptable risk” of terror attack due to policing cuts, it has been warned.
The Defence Police Federation, which represents civilian Ministry of Defence Police officers, said the force is facing a cut of up to £15 million from its £167m budget.
In an open letter to new Defence Secretary Gavin Williamson, the Federation said “deplorable” decision-making had undermined those responsible for guarding the Trident nuclear deterrent.
The MoD said the force had adequate numbers with which to do its job.
The MoD Police are also responsible for guarding munitions sites and the new aircraft carrier HMS Queen Elizabeth when in port.
Federation chairman Eamon Keating said security at MoD sites around the country was falling below acceptable and agreed levels.
He warned that “hard targets” including military bases are at a “high risk” of terror attack but are seeing their police presence significantly reduced.
He said: “MoD sites around the country are now below the minimum level security needed to protect them from a terror attack.
“They are instead routinely running at the level of maximum risk as a starting point, moving beyond this daily. We’ve seen that terrorists aren’t afraid to attack well-guarded sites. We must believe they wouldn’t hesitate to attack military establishments.”
He added: “The risks are evident, yet decisions are being taken by officials that prioritise the bottom line over the threat to personnel and assets that in some cases cost tens of billions.
“It is entirely the wrong approach. We have tried to make our concerns known privately but the risk to security and public safety leaves us obligated to alert the Secretary of State to what is an unacceptable situation.”
The Federation also warned the MoD’s plans would reduce the number of firearms officers who can be deployed nationally to protect the public in the event of a critical incident.
The MoD said arrangements were being kept under continual review and frequently tested.
An MOD spokesperson said: “The MOD Police has enough people to meet its commitment to protecting key sites across the country.
“We take the safety and security of such sites very seriously and we would never put them, or the people who work within them, at risk.”