oppugn vs call into question

oppugn and call into question both are verbs.

Word	Noun	Adjective	Verb	Adverb
oppugn	No	No	Yes	No
call into question	No	No	Yes	No

As verbs, oppugn and call into question are synonyms defined as:

oppugn and call into question: challenge the accuracy, probity, or propriety of

Other synonyms of oppugn include question.

oppugn (verb)	call into question (verb)
challenge the accuracy, probity, or propriety of	challenge the accuracy, probity, or propriety of