0 a strong personal interest in something because you could get an advantage from it:
1 an interest in influencing something so that you can continue to benefit from it:
She said the port has a vested interest in protecting the community's environment.
The British vested interests didn't regulate their own industries, as the Chinese state firms do.
2 a strong reason for supporting a particular action which will give you a personal or financial advantage:
3 people or organizations with a financial or personal advantage in a system, situation, etc., used especially when they refuse to allow changes to it that would cause them to lose this advantage: