As long as people keep voting for these politicians, nothing will change. 

We should stop voting for them.  Just stay at home, and refuse to vote.  

Suppose we all did this, and none of us voted in the General Election.  What would this cause?  Two things:

1. It would deprive politicians of any claim that they have a "mandate from the people".

2. It might lead to changes in the politcal system.

But there won't be any changes if people keep "voting" . Isn't that obvious?