"MP's own shares and get paid as shareholders.
The companies using this are the ones probably paying the MP's."
Leaving aside the double use of a grocer's apostrophe what are you actually saying here?
Are you claiming that MPs, instead of being paid a parliamentary salary, are using personal service companies to get paid? If so what's your evidence for this?
Or is this a belief in some great conspiracy where only a few powerful people own all the shares and run the economy accordingly? If so then you should be aware that shareholding is a great deal more widespread than you think. Are you a member of a company pension scheme? Then, indirectly, you are a share holder. Do you have a personal pension or a life insurance scheme? Then you are a shareholder. Or almost any other form of savings? Does your employer have an employee share scheme?