The NDP used its majority in the legislature to approve the law, which cuts the number of seats in the house to 51 from 52 and merges four ridings intended to represent the province's black and Acadian populations with other ridings.
Fisheries Minister Sterling Belliveau used the special permission he was given by Premier Darrell Dexter to oppose the bill because it splits his Shelburne riding. The legislation passed by a vote of 26 to 22.
The Acadian Federation of Nova Scotia said it will fight the new map in court because it takes away the voice of French-speaking people in the ridings of Clare, Argyle and Richmond, which are among those being merged with neighbouring electoral districts.
Federation president Justin Mury said the legal challenge will argue the province's linguistic minority wasn't properly considered in rewriting the boundaries.
"We think it's very unfortunate and it's definitely going to silence our voice in the legislature," he said.
Both opposition parties voted against the new map, arguing the government interfered by rejecting the interim report of the independent Electoral Boundaries Commission, which recommended continued protection for the four designated minority ridings.
Michel Samson, a Liberal who represents the riding of Richmond, said the government should have consulted the province's minority groups to find a solution that protected their rights while dealing with shifting populations in rural areas.
"It's unfortunate that we find ourselves in a process that should have been non-political, that should have been free of political interference, instead we're left with a process that was tainted from day one," he said.
The Acadian federation also accused the government of interfering in the work by the independent commission by insisting it adhere to a rule that says all ridings in the province should have a population that does not vary more than 25 per cent from the overall average of about 14,000.
In its final report in September, the commission recommended the four minority ridings — including a Halifax-area riding that has a large black population — should be merged with neighbouring districts to ensure relatively equal representation.
Progressive Conservative Chris d'Entremont, who represents Argyle, said consultations that were held to rewrite the map failed.
"It's not what people asked for," he said. "Nowhere along this did the people of Nova Scotia get what they asked for. And do you know why? Because politics got involved."
Dexter has said the commission's terms of reference provided for a balance between minority rights and equal representation, and he expects the new map will withstand any legal challenge.
In opposing the bill, Belliveau blamed the commission for splitting Shelburne County in its final report and told the legislature he was standing with his constituents.
"It is because of them that I am unable to support this legislation," he said. "The people of Shelburne County were unanimous to keep the seat of Shelburne County intact."
Debate on the bill turned testy when Leonard Preyra, who is minister of communities, culture and heritage, accused the opposition parties of hypocrisy on minority rights.
"If they were truly committed to having an African-Nova Scotian in their caucus, perhaps they would have considered nominating more African-Nova Scotian candidates," he said.
"We will not be lectured to by one of the most homogenous oppositions that we have seen in the history of this province."
Nova Scotia is required by law to review its electoral boundaries every 10 years.