vested interest
US /ˈves.tɪd ˈɪn.trəst/
UK /ˈves.tɪd ˈɪn.trəst/
1.
a personal stake or involvement in an undertaking or state of affairs, especially one with an expectation of financial or other gain
:
•
As a shareholder, he has a vested interest in the company's success.
•
The politician's decision was influenced by his vested interest in the new development project.