The $15.36 million, which the government assures will not affect the force's front line, will be deducted from ACT Policing's annual budget of $150 million over the next four years.

The government has been accused of hiding the cuts in Tuesday's budget, which was sold as providing a ''Safe and Secure Canberra'' and bringing ''More Police and Firefighters''. Police Minister Simon Corbell said on Thursday the modest cuts were not expected to cause the ''compromising of front-line response capabilities".

He said he had made it ''very clear'' to the force, which polices the city on an annual contract and is not directly part of the ACT government, that the savings should not affect its ability to reduce crime rates and respond to incidents.

But the Australian Federal Police Association has warned the cuts, while having minimal impact at first, would begin to bite in the final two years.

It fears between 40 and 45 officers may be cut as a result, which equates to more than the existing staff numbers at Gungahlin police station.

AFPA chief executive Dennis Gellatly said ACT Policing could not be expected to provide the same level of policing service to Canberra.

"Canberra is a growing city that requires increasing police services, not less," he said.

"It appears that the ACT government intends to wind back the clock on policing numbers which, in three to four years, could result in the lowest police numbers per capita in Australia.''

The AFPA said the government had failed to consult with senior members of ACT Policing, including the chief police officer and union leaders, before the budget decision.

Mr Corbell said he would not detail internal budget discussions but said there had been ''no surprise'' over the measures in his discussions with ACT Policing to date. The $15 million in savings will be made as the government pours millions into the RAPID licence plate recognition technology, which will partly help increase revenue from traffic fines by 28 per cent in 2013-14.

Opposition police spokesman Zed Seselja has accused the government of burying the numbers in the budget papers.

''ACT Labor has betrayed the people of Canberra by trying to hide the fact that they are making significant cuts to the police force,'' Mr Seselja said.

''I hear frequently from Canberrans that they are worried about safety in their neighbourhood. They would clearly oppose any cuts that will affect law and order for them and their families.''

The AFPA said the recent declines in crime rates were a result of investment in police numbers and resourcing over the past five to eight years.

Mr Gellatly, a former senior ACT police officer of considerable experience, said the compounding effect of the savings would hurt ACT Policing.

''We believe the Canberra community should not accept a compromised policing service, particularly when there is talk of increasing the number of politicians,'' he said.