Police will have to be taken off the front line and their numbers reduced unless the Scottish Government helps forces cover the spiralling pension budget, according to one of the country's most senior officers.

John Vine, Chief Constable of Tayside, believes the pensions funding gap is one of the biggest challenges facing forces and that staff numbers will be affected unless pensions are taken into central control.

Speaking exclusively to The Herald just weeks before he leaves the force to take up his position as head of the new Border and Immigration Inspectorate, Mr Vine also warned that structural change for the currrent eight forces is "inevitable".

And he questioned whether the country requires both the Serious Organised Crime Agency and Scottish Crime and Drug Enforcement Agency when both have similar functions.

Mr Vine said: "Unless police pensions are taken to the centre and out of operational policing budgets then chief constables are going to be forced to take the decision of taking police officers off the streets.

"Last year in Tayside we offered £1m in savings to the council to help them balance the books. Up until now it has had no impact on direct policing but we cannot go on like this. Some 80% of any force's budget is manpower and pensions will negate any of the very welcome increase in budgets."

A Scottish Government spokesman said: "The Scottish Government is examining the feasibility of centralising the funding and administration of police pensions. It is a complex area and if feasible would take some time to achieve."