Nicholas Higgins is Margaret Hale's main connection to the working class folk of Milton. She first meets him when she offers a bouquet of flowers to his sickly daughter, Bessy. She even offers to visit his house to help cheer Bessy up when she's ill. But Nicholas isn't used to the polite customs of southern England. He meets Margaret's offer with suspicion, saying, "I'm none so fond of having strange folks in my house" (1.8.41). At first Margaret finds this response offensive, but then she realizes that as a working man and a union leader, Nicholas isn't the most trusting guy in the world. He's used to being pushed around, and used to having to be kind of harsh in response.
On top of being a suspicious dude, Nicholas is super proud, even though he doesn't have much education or money to his name. When the time comes for him to ask for a job from Mr. Thornton, he tells Margaret, "It would tax my pride above a bit; if it were for mysel', I could stand a deal o' clemming fist; I'd sooner knock him down than ask a favour from him" (2.12.52). Nicholas would prefer to get his dinner by fighting than by begging for a job. That's the kind of rough world he's used to. Unfortunately, his career as a labor organizer has made him hated among Milton's employers and he needs to take what he can get in order to help his family. He's a stand-up guy like that.
By the end of the book, Nicholas Higgins goes to work for Mr. Thornton and advises him on how to keep the workers happy. Mr. Thornton isn't interested in another labor strike. He even makes some serious strides toward leveling the playing field between his workers and himself. All in all, Elizabeth Gaskell tends to hold up the relationship between Thornton and Higgins as a good example of bosses and workers cooperating and listening to one another's points of view.