Police Scotland’s annual budget is down £200 million since the devolved force was created, amid warnings that current officer numbers are “not sustainable”.
Chief Constable Iain Livingstone told the Scottish Police Authority (SPA) that hundreds of millions of pounds have been removed from “the core cost of policing” since Police Scotland came into being in April 2013.
His funding concerns were echoed by vice chair of the SPA watchdog, David Crichton, who said that a “structural deficit” within the force is making current officer numbers untenable.
The warnings come ahead of a busy year for Scottish officers, who will have to police the UN’s COP26 climate change summit in Glasgow, Euro 2020 football matches, major environmental protests and the “growing” number of loyalist marches.
"Frankly, current officer numbers are not sustainable within the existing budget so something has to change on that front,” Mr Crichton told the SPA meeting in Edinburgh today.
"There is a structural deficit in the policing budget. It's simple arithmetic, it's not complicated mathematics.
"The deficit is simply going to continue to increase if something does not change.
"With almost 90 per cent of the budget allocated to officer and staff costs, it does mean that difficult choices are going to have to be made over the next weeks and months - difficult choices by Government, by the authority and by Police Scotland.”
Mr Crichton’s comments follow months of turmoil for Scottish policing, after Prof Susan Deacon resigned as head of the SPA in December last year saying the system is "fundamentally flawed."
Prof Deacon had become "increasingly convinced" that the arrangements for overseeing the running of Police Scotland are not fit for purpose.
The force faced increasing financial pressure this week due to the spiralling security costs for the UN climate change conference, the COP26, which will be held in Glasgow in November.
Mr Livingstone told the SPA that the conference will be one of the largest events ever staged in the UK and that he expects the policing costs to be more than £200 million.
Officers will be brought in to Scotland from every force in the country, the meeting was told, with the cost of housing running into tens of millions of pounds. A deposit of £2 million to secure the accommodation is due as early as next month.
The COP26 - which stands for the 26th session of the Conference of the Parties - will host up to 90,000 people, including delegates, heads of state and media, over 12 days from 9-20 November.
Police are also expecting a climate change march to coincide with the summit involving up to 500,000 demonstrators.
Assistant Chief Constable Bernard Higgins said that the event will require the same number of officers as the 2012 London Olympics, adding: "This is going to be without question the biggest policing operation in recent years.”
There is growing pressure on the UK government to foot the bill for COP26, with Mr Livingstone yesterday telling the SPA meeting: "There cannot be detriment to the funding of the police service in Scotland as a result of us delivering on the United Kingdom Government's intention to host this conference on climate change in Glasgow.
"I'm not being ridiculous in seeking full cost recovery, I am being absolutely legitimate for the public purse and for the police service."
The UK government has said discussions with the Scottish government on the conference costs are "currently ongoing".
Highlighting the shrinking budget of policing in Scotland since it became devolved to Holyrood, Mr Livingstone told the meeting: "The core cost of policing is £200 million less every year than it was prior to Police Scotland coming into being (in April 2013).
"Our deficit is because our budget has been cut even greater than the savings that we've managed to achieve.
"So my pitch is, can we get some of those savings back?"
Official figures showed there were 17,256 full-time equivalent police officers in Scotland at the end of September 2019.