…After Russia invaded. War powers to disallow treasonous activity and undermine a war effort are not unusual. You think Russia doesn’t suppress opposition media or politicians? Get your head out of the sand.
Churchill arrested all British pro-Nazis and shut down their media. All the open party leaders like Oswald Mosely were interned (without charges) for the duration. And more yet- an interesting article -
https://www.timesofisrael.com/the-men-and-women-who-plotted-to-stab-britain-in-the-back-during-wwii/