take up the cudgel(s)

take up the cudgel(s)

To defend, show strong support for, or argue on behalf of someone or something. Often followed by "for" or "on behalf of." People from across the country are taking up cudgels on behalf of the young man being held by police. He's got plenty of money to hire a proper legal team. I don't think he needs the likes of us taking up the cudgel.
See also: take, up
Farlex Dictionary of Idioms.

take up the cudgels

or

take up the cudgel

If you take up the cudgels for someone or take up the cudgel for them, you speak or fight in support of them. The trade unions took up the cudgels for the 367 staff who were made redundant. We are hoping that the government will take up the cudgel on our behalf. Note: A cudgel was a short, thick stick that was used as a weapon in the past.
See also: cudgel, take, up
Collins COBUILD Idioms Dictionary, 3rd ed.

take up the cudgels

start to support someone or something strongly.
See also: cudgel, take, up
Farlex Partner Idioms Dictionary

take up the cudgels

To join in a dispute, especially in defense of a participant.
See also: cudgel, take, up
American Heritage® Dictionary of the English Language, Fifth Edition.
See also:
  • take up the cudgel(s) for (someone or something)
  • take up the cudgels for somebody/something
  • take up the cudgel(s) on behalf of (someone or something)
  • keep (someone or something) for (someone or something)
  • keep for
  • intercede with (someone or something)
  • procure
  • procure (something) for
  • convey (something) from (someone or something)
  • mouthpiece