Guardian fights to have European expelled (5)

I believe the answer is:

argus

'guardian' is the definition.
(term for a guardian, from the mythological figure)

I don't understand the rest of the clue.

(Other definitions for argus that I've seen before include "Giant with one hundred eyes in Greek mythology" , "Alert watchman" , "Many-eyed giant" , "Many-eyed mythical monster" , "Hundred-eyed giant in mythology" .)

I've seen this clue in The Times.

Want a hint initially instead of a full solution? Install my app