The introduction of a single police force will mean job losses, the Justice Secretary has conceded.
But Kenny MacAskill pledged there would be no compulsory redundancies as a result of the shake-up. He also vowed that frontline policing would be maintained in the move from eight area police forces to one national body.
Scotland's eight regional police and fire services will be merged into respective single units by April. The change could save £1.7 billion over 15 years by reducing duplication.
The Justice Secretary told BBC Radio Scotland: "Yes, there will be job losses. I can not guarantee a job to eight chief constables, there will only be one. Equally, we cannot have eight HR departments, eight PR departments, eight communications departments."
Mr MacAskill spoke out on the issue the day after Holyrood approved legislation to create the new single police and fire services.
Speaking on the Good Morning Scotland programme, the Justice Secretary said: "As some chief constables will go, so will some chief constables' drivers and some chief constables' support officers.
"But as a consequence of this, we will ensure we maintain frontline policing. There will be a loss of some backroom staff, that I accept, the same as there is a loss of chief constables, because we cannot do things eight times over."
But he insisted the shake-up was necessary, saying that without it Scotland would be in a similar situation to England and Wales, where he said 16,000 frontline officers were being lost.
"The status quo is not an option," Mr MacAskill said. "If we don't change, what will play out is the same situation south of the border, loss of frontline officers and an attack on the terms and conditions of officers who serve. We will not countenance that as an SNP Government."
Mr MacAskill said there was a guarantee of no compulsory redundancies as a result of the change, but added it was ultimately for the new chief constable to decide the number of staff and where they should be located.