on shaky ground
US /ɑn ˈʃeɪki ɡraʊnd/
UK /ɑn ˈʃeɪki ɡraʊnd/

1.
站不住脚, 岌岌可危
in an uncertain or unstable position; likely to fail or be challenged
:
•
His argument was on shaky ground because he lacked sufficient evidence.
他的论点站不住脚,因为他缺乏足够的证据。
•
After the scandal, the company's reputation was on shaky ground.
丑闻之后,公司的声誉岌岌可危。