Police officers in Glasgow could take industrial action after the force rejected a "derisory" flat £565 annual pay increase.
The Scottish Police Federation (SPF) turned down the pay deal and said any action it takes would be "impactful".
SPF general secretary Calum Steele told BBC Scotland: "There is palpable anger across our workforce.
"The options we are looking at are wide and they are varied.
"They will be impactful, and be in no doubt that the willingness of the police service to simply stand back and accept this derisory offer, at a time that other bodies and other workers will be taking much more action than we are capable of doing, the notion that we are going to accept that and stay silent is simply a fantasy."
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Members of the force are restricted on how they can protest, for legal reasons, but Mr Steele said SPF members were willing to take action "for many months" unless "significant improvement" is made.
The SPF, which represents all officers of varying ranks, asked for 3.4%.
It said the current offer amounted to about 2% for most members and 1% for its higher-earning members.
A Scottish Government spokesman said negotiations over pay were "ongoing".
Mr Steele added: "There are many options that are available to us. We're looking strongly at all of them.
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"The goodwill that this police service runs on is undoubtedly disappearing faster than snow off the proverbial dyke."
Police payments are negotiated by the Police Negotiating Board, which includes Police Officer Staff Associations, Scottish Police Authority, Police Scotland and Scottish Government.
A spokesman for Police Scotland said they were unable to comment while the discussions were ongoing.
Last year officers received a £700 pay rise and a separate non-consolidated payment of £250.
