Police officer numbers in Scotland could fall below 16,000 next year without an increase in funding, the Scottish Police Federation (SPF) has warned.

Police funding has been discussed in recent weeks following a call from Police Scotland Chief Constable Jo Farrell for £128 million more than last year.

In a letter to SNP Justice Secretary Angela Constance ahead of the budget announcement next week, the SPF said officers are “policing with one arm tied behind our backs and our fingers crossed”.

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The body, which represents rank-and-file officers, added: “We now work to an establishment figure of 16,600, but subject to an ongoing recruitment freeze, this figure will fall to below 16,000 by April 2024.

“With the threat of an extended recruitment freeze for the entire financial year of 2024-2025, who knows where this number may eventually fall to?”

Budget cuts and reductions in officer numbers, the SPF said, will lead to “communities being less safe”, an increase in crime and stress and mental health issues for officers.

The letter, signed by general secretary David Kennedy and chairman David Threadgold, said: “The fact is that the public are losing faith in and support for the police and this will continue until our ability to police with consent will be negatively impacted.

“This sorry situation is bound to get worse unless an immediate injection of funding is provided to the police.

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“We note that the chief constable has sought £128 million over flat cash and our view of this is that it is extremely conservative.

“Within that figure, £26.4 million has been identified for capital, but we know that to bring our estate up to an acceptable standard will take anything up to £800 million. This is the result of years of under-funding and we must begin to repair the damage.

“How can we ever hope to change the culture within our organisation or re-engage with our communities against a backdrop of training embargoes, hundreds of officers leaving the service and not being replaced due to recruitment freezes, and a continuous and relentless demand for our service?

“Without the correct investment, it is simply not possible.

“The communities in all areas of Scotland are suffering negative consequences of police under-funding.

“The service we are providing is stretched and, in many cases, simply not good enough.

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“Our members are suffering too, from overwork, stress, sickness, disruption to what should be time off and from feelings of low value and respect.”

The letter follows an announcement from Police Scotland that 29 buildings – including police stations – are to be closed and sold off, with a consultation launched on the future of a further 15.

The SPF said this will mean more than 200 police offices and buildings have been closed since forces were merged to create Police Scotland in 2013, adding: “Public safety and security are at risk, and we can only hope and pray that we do not witness a disaster.”

Speaking at a meeting of the Scottish Police Authority last month, Ms Farrell said: “Without funding over and above flat cash, we will be unable to recruit police officers in 2024-25.

“My experience in England is that would significantly impact community policing and proactivity like drugs raids.”

Scottish Conservative justice spokesman Russell Findlay said: “Scotland’s frontline police officers cannot sustain any further cuts from the SNP.

“Shona Robison should do the right thing and properly fund policing.

“Failure to do so will result in even fewer officers, putting our communities at greater risk.”

A Scottish Government spokesperson said: “Policing is a priority for this Government which is why, despite difficult financial circumstances due to UK Government cuts, we increased police funding by £80 million to £1.45 billion in 2023-24.

“There are 379 more officers than in 2007 and Scotland continues to have more police officers per capita than England and Wales.

“The Deputy First Minister said that the UK Government’s autumn statement delivered the ‘worst case scenario’ for Scotland’s finances.

“Ministers are assessing the full implications of that statement as they develop a Budget that meets the needs of the people of Scotland, in line with our missions of equality, community and opportunity.”