A few instances where uniformed LEOs in the USA were forbidden to be armed by their appointing authority - chief, administration or governing body. Locally I know of one campus police dept, and state comm'l vehicle officers, where policies were changed by labor grievances filed with the state. Another state agency armed their LEOs before a labor action was filed. Actions were taken up as "unsafe working conditions" or "hazardous workplace without recognized necessary equipment". Where the officer's complaints prevailed, employers were cited for workplace violations and fined for every day out of compliance. The "whistleblower" protection from employer retaliation was available, unknown if it was invoked or necessary.
Labor unions may be of little help, as most general "public employee" unions (include clerks, cooks, and social workers) are clue-less on police matters and the day-to-day risks. LEOs are a small minority of their membership, and the prof. union leaders may take a practiced "guns are always bad" position.
It may take thousands of individual labor grievances, working outside of the established unions, from individual UK officers to get the issue into the daylight. We call it "grass roots" political action. If thousands of individual UK police officers pile the labor grievances on "the system", some Minister or politician has to account for the dispositions or findings. We all know how politicians like accountabiity..........
Old people may not live to see the collapse of our Nation. The rest of you may not survive the collapse.
A lie told often becomes truth. (Valdimir Ilyich Lenin)