The Scottish Police Authority plans to cut the number of police officers in Scotland.
Financial documents propose cutting police by 100 through "freeing up" officers in back office roles, saving £2.7 million.
In its draft budget report, the authority said this means "Scotland will continue to receive the same level of front line policing as it has for the past 10 years, but at a lower cost to the taxpayer" but the plans have been criticised by the Scottish Police Federation.
SPF vice-chairman David Hamilton raised concerns about the proposal, including questioning what constitutes a front line officer and the evidence to back up the 100 figure.
He said: "What is the front line? Is it the control room? Is it CID? There's no definition of front line, it's just nonsense.
"They are saying it's coming from corporate services but they need to tell us what corporate services are they not doing? I'm not aware of anyone sitting twiddling their thumbs."
"100 is a suspiciously round number. There's nothing to say they are going to take an evidence-based approach to this... This just looks like a back of the fag packet calculation," he added.
"Demand is at an all time high for police services. There's no capacity within the organisation for any cuts."
The most recent figures show Police Scotland had 17,256 full-time equivalent officers on December 31, 2017.
The draft 2018/19 budget allows for 17,134 police officers, which would take the numbers below the Scottish Government's commitment for a 1,000 increase from 2007, scrapped in 2016.
The draft budget report, due to be discussed at the SPA board meeting on Thursday, also highlights an expected £35.6 million operating deficit in 2018/19.
The budget gap is down from the £47.2 million in the previous year's budget and part of a three year commitment to the Scottish Government to eliminate the deficit by 2020/21.