Objector

Ob·ject'or noun [ Latin , an accuser.] One who objects; one who offers objections to a proposition or measure.
Found on http://www.encyclo.co.uk/webster/O/3

Objector

• (n.) One who objects; one who offers objections to a proposition or measure.
Found on http://thinkexist.com/dictionary/meaning/objector/
No exact match found