Over 400 Russian 'diplomats' (read: spies) have been expelled around the world, but why hasn't UK kicked out any? Three hypotheses

Since the beginning of the invasion of Ukraine, over 400 Moscow officials have been expelled around the world (30 by the Italian government). In London one wonders what is waiting for Johnson to do the same, but after the attempted poisoning of Skripal ...
Since Vladimir Putin initiated the invasion of Ukraine on February 24, over 400 Russian diplomats h…