So politicians tend to listen to "groups" as opposed to individuals, and we are in a "group" which by law and custom, remain silent. You can share your concerns with friends, family and neighbours (in a non partisan fashion; "these are the facts, and they seem to lead to this conclusion") and they can speak to the politicians. One of you might not have clout, but six or seven letters from voters attracts some attention, and if your friends and neighbours each tell one of their friends and neighbours (and so on), then real attention gets paid.