Police Scotland officers are threatening legal action against plans to ban beards on the frontline from this month.
Sky News understands the new clean-shaven policy will come into action in the coming weeks, forcing hundreds of staff to shave off their facial hair.
The force said the move was to comply with face-fitted PPE masks.
Police Scotland has 16,615 full-time officers, making it the UK’s second biggest forces after London’s Metropolitan Police.
The Scottish Police Federation, which represents rank and file officers, confirmed four workers were pursuing employment tribunal cases.
General Secretary David Kennedy told Sky News: "The SPF has been inundated with officers’ complaints.
"The Health and Safety Executive guidance is that a RPE (Respiratory Protective Equipment) policy should only be utilised as a last resort and there have been relevant questions raised as to why this policy is now being proposed.
"There are serious concerns in relation to the proposed implementation of the policy and its proportionality to risk.
"We are currently supporting several members who have lodged employment tribunal cases relating to the policy and have sought legal opinion relating to health and safety, discrimination and human rights."
The Met’s most-recent facial hair policy from September 2022 states beards and moustaches are allowed for London officers.
It says "they mustn’t look unkempt. Keep them trimmed and smart."
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Police Scotland has insisted there will be exemptions to the ban including for religious, cultural, disability or medical reasons.
Assistant Chief Constable Alan Speirs said: "The safety of our officers and staff is a priority and the policy around the use of respiratory equipment is being implemented to protect those on the frontline.
"Significant learning from the COVID pandemic identified that the FFP3 mask – which is face-fitted and requires users to be clean shaven – offers the most appropriate and effective respiratory protection to officers and staff.
"The respiratory protective equipment policy mandates that, where it can be reasonably foreseen that an officer or member of staff will use an FFP3 mask in the course of their duties, they should be clean-shaven."
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