n. a person who takes a strict position (on something).
Tom is sort of a hardliner when it comes to spending public money.The mayor is a hardliner on the question of care for the elderly.
hardliner
Someone who has an unyielding, inflexible belief in some person or thing. Susan's not a hardliner, so I really think she'll listen to your views on the matter.
hardliner
n. a person who takes a strict position (on something). Tom is sort of a hardliner when it comes to spending public money.