looking for a word that communicates following a measure will lead to many negative consequences
UPDATE:
I would like to use the word as I write about proposed policy changes; namely, a bill in the senate proposes to establish the minimum down payment of a mortgage to 5%. A person giving testimony against this measure, argued that mandating down payment levels can have many negative consequences.
That which acts against what you are trying to do is detrimental, though in order to use it properly, you would have to say what it is detrimental towards.
If it were a bill that causes greater difficulty in purchasing homes, you would say it is "detrimental to home purchases", or if it is adversely affecting stocks, you could say it is "detrimental to the stock market".
Or if you want to indicate a great number of negative consequences to a plan, you could say that it has "many detriments".
Assuming that the things that the person is describing as negative consequences are not the same effects others are describing as positive, I would probably say downsides, side effects, or unintended consequences.
Pernicious (or "harmful") convey the idea of negative consequences, specialy if it is not obvious at first glance.
"Pernicious" definition: causing insidious dommage or harm often in a way that is not easily seen or noticed.
Example: She thinks television has a pernicious influence on our children.
The expression, "slippery slope" is used in pop culture to describe the scenario you have mentioned.
