SCOTLAND'S most senior frontline officers have threatened to take legal action against chief constables if they continue to promote police regardless of cuts expected in a year's time.

The Association of Scottish Police Superintendents (Asps) has warned the continuing promotion of officers is "untenable" and that a moratorium should be imposed.

A number of forces have run recent promotion drives. More than a dozen superintendents and a number of inspectors have been appointed across the country.

The move to a single force on April 1, 2013, will require a "rationalisation of senior ranks" and Asps fears experienced superintendents will be forced out. Fully sworn officers cannot be made redundant, but under Regulation A19, officers with more than 30 years' service can be asked to leave.

One officer said: "It's like a game of musical chairs. Everyone knows we are moving to a single force and that next year less senior ranks will be required but they seem to want to get as many people promoted from their force area as possible, so that when the music stops they're in a stronger position."

Chief officers have pledged to cut £5.4 million through cutbacks and efficiency savings in senior ranks. Superintendents earn around £62,000.

A letter from Asps president David O'Connor to the Association of Chief Police Officers in Scotland (Acpos) calls for a more "collegiate" response from the eight chief constables. It says the continuing promotion of officers sends out the wrong message when police are meant to be "sharing the pain".

The letter states: "We would suggest the current situation is simply untenable and the service – and Acpos – has reached a point where a moratorium should be placed upon substantive promotions. This decision must be predicated on the realities of future convergence.

"Some chief constables might argue that the absence of clarity regarding the new structures renders any such decision unnecessary at the present time and that existing local procedures should therefore continue. We would suggest that this would be a short-sighted view. You will appreciate that our major concern is that Regulation A19 will be used to reduce management posts in large numbers after the new police service is introduced. Should that situation arise, we would legally challenge it as a staff association.

"Part of that challenge would include an assertion the situation could have been avoided if a more consistent and corporate approach had been taken at an early stage by chief constables – on the reasonable assumption by them that management restructuring would be a major element of implementing the new structures – to suspend substantive promotions until proper clarity was achieved regarding the number of senior ranks required."

Asps has called for the single force's new chief constable to be appointed as a matter of urgency. It believes the new chief needs to be in place as soon as possible to make key decisions.

"This will include an assessment of how many superintendents and other senior ranks are required by the single force.

Assistant Chief Constable Cliff Anderson, general secretary of Acpos, said: "The promotion of officers at any level in a force is a matter for the chief constable and will be based on operational needs and force balance.

"The resilience and efficiency of the eight individual forces is extremely important as we move towards police reform and a single Scottish service.

"We must also maintain the excellent service levels for which Scottish policing is well known and for that we need the right levels of officers at senior and supervisory ranks."