• Justice secretary Kenny MacAskill meets PCs Carol Menzies and Nick Johnston, who were joining the force as new recruits, at Howdenhall Police Station in Edinburgh Picture: Julie Bull
Kenny MacAskill urged forces to share services when he admitted that the police's current structures were no longer possible in the face of 35 billion cuts from the Scottish public services budget over the next 15 years.
He raised the spectre of radical reorganisation of the police when he said that back office mergers would have to take place across forces to reduce duplication of effort. Such a move would inevitably lead to many job losses.
"It will not be sustainable to carry on as before," Mr MacAskill warned.
"We are a small country and we can no longer afford to do everything eight times over. We cannot afford for any options to be off the table."
Mr MacAskill's remarks to an Association of Chief Police Officers in Scotland (Acpos), meeting in Cumbernauld, were interpreted by opposition politicians as a sign that amalgamations could be in the pipeline.
Restructuring of Scotland's police forces has proved a deeply divisive issue in the past.
At the end of last year, a report by Bill Skelly, HM Inspector of Constabulary for Scotland, suggested the creation of a single Scottish force to meet the challenges of the economic crisis.
A similarly radical approach was recommended by Mr Skelly's predecessor, Paddy Tomkins.
Mergers have been fiercely resisted by chief constables who are opposed to the centralisation of policing power and want forces to retain their distinct identities as Strathclyde Police; Lothian and Borders Police; Northern Constabulary; Grampian Police; Tayside Police; Fife Constabulary; Dumfries and Galloway Constabulary and Central Scotland Police.
When asked about Mr MacAskill's remarks, the Scottish Government said ministers remained committed to all of Scotland's police forces.
His comments, a Scottish Government spokesman said, were about forces "working together to achieve efficiencies".
Mr MacAskill said this year's police budget of 1.4bn was 235 million a year more than under the previous Labour/Lib Dem Scottish Executive.
But he added that those funding levels could not continue. There was a need for "fresh thinking and new approaches".
He said: "We are entering a period where we will face major economic and financial challenges for several years.
"We need to be planning now for a new financial climate that lasts for perhaps a generation – there can be no doubt that we are entering a phase of unprecedented challenges.
"Whether it is procurement, IT, or back office functions, we need to focus on cutting duplication and finding more efficient ways to work.
"It is time for some fresh thinking and new approaches. We cannot afford for any options to be off the table, whether this be streamlining structures or new ways of working."
Union leaders representing civilian police staff, who man back office functions, last night expressed concern about Mr MacAskill's speech.
"Yes, we are worried about job losses," said Peter Veldon, of Unison, the lead negotiator in police staff discussions in Scotland.
"This does sound bad on the face of it, but we need to see the details. We have been part of the police civilianisation process, brought in to get more officers on the beat, and we very much hope that continues."
Moves to centralise police operations have proved controversial in the past. The creation of a Scottish Policing Board last year to tackle terrorism and people trafficking was dismissed by critics as a waste of money.
Yesterday Mr MacAskill admitted that he could not predict how Scottish policing would change in the long term.
"I do not have a blueprint for how Scottish policing will look in five years' time, or 15 years' time. But looking at the figures, we know it will not be sustainable to carry on as before."
Mr MacAskill was criticised by the Liberal Democrat justice spokesman Robert Brown, who said the SNP was giving mixed messages on its commitment to Scottish police forces.
Mr Brown said: "The government is giving very mixed messages about police funding and this casts serious doubt, both on their stated commitment to retaining eight police forces in Scotland and to achieving and keeping 1,000 extra police officers.
"Political fudges have been the hallmark of the SNP government and this simply won't do on this important issue."
Labour's justice spokesman, Richard Baker, agreed.
He said: "We need to have clarity from the justice secretary. By saying that we can't do things eight times over, he seems to be looking at reconfiguring our police forces. What we need to have from him is some honesty.
"This clearly opens the door for the debate on how many police forces there should be."