Paul Maskey was elected in the West Belfast district formerly held by Sinn Fein leader Gerry Adams. Adams gave up his Westminster seat to stand for the Irish parliament.
Maskey said vote counting showed he got at least some support from Protestants and referred to the Shankill Road, the main artery in one of Belfast's most loyalist neighborhoods. He received about 70 percent of the vote in the by-election.
"I got votes out of every box opened and I think that it's great. I try to work, and the party tries to work, for as many people as possible," he said. "I don't see any borders in West Belfast. People from every district, including the Shankill and Blacks Road, come to our offices. I would like to see a day when I can open a surgery (for constituent services) on the Shankill Road."
Like Adams, Maskey will not take his seat in Parliament because he refuses to swear an oath of allegiance to Queen Elizabeth II. But he said he does not believe Sinn Fein's abstentionist policy will hurt his constituents.