HALIFAX - Nova Scotia's premier says an independent commission examining electoral boundaries has violated its mandate by recommending the provincial government retain four so-called protected ridings for francophone and black minority groups.

Darrell Dexter said Tuesday that the Electoral Boundaries Commission should have obeyed a term of reference that requires constituencies be within 25 per cent of the average number of electors -- a criteria none of the minority group ridings meet.

The eight-member commission said in an interim report last week that it based its recommendation on another term of reference that allowed commissioners to consider linguistic and cultural diversity.

Dexter said the commissioners' interpretation is incorrect and the population requirement should prevail.

"I do not think it fulfils the mandate set out in the terms of reference and I fully expect that any final report will meet that responsibility," said Dexter in a telephone interview.

The final report is due Aug. 31.

The requirement that ridings be within 25 per cent of the average number of electors has drawn criticism from Acadian communities around the province, including a protest by francophone high school students who confronted the NDP finance minister during a visit to Yarmouth.

Commission chairwoman Teresa MacNeil said she and other commissioners based their findings on public hearings in the spring and decided they couldn't recommend abolishing the ridings.

"To move the protected constituencies in either direction would mean they would lose the character for which they were designated in the first place," she said in a telephone interview.

"It became an untenable situation."

She also said the commission only needs to be "guided" by its mandate, according to its terms of reference.

"We felt we had that much latitude," she said. "It was not a matter of defiance."

One commissioner -- Dalhousie University professor Jill Grant -- dissented, saying the commission went beyond its authority by recommending the protected ridings be kept.

Both opposition parties have supported the retention of the protected ridings, saying they preserve the rights of minority groups in the province.

Liberal Leader Stephen McNeil said he suspects the New Democrats are upset because in effect, the commission is recommending the elimination of ridings in Pictou County and Cape Breton that are held by NDP members and the retention of opposition-held minority ridings.

"The commission went out and listened to Nova Scotians and didn't follow through with a pre-determined notion for the NDP," he said.

"If the premier wants to get rid of the minority ridings, have the courage to stand up and say so."

Conservative Leader Jamie Baillie said Dexter is ignoring the input of Nova Scotians, accusing the government of political interference.

"The government is the author of its own misfortune with this," Baillie said. "They tried to pull a fast one by imposing an NDP-only terms of reference on the committee."

Attorney general Ross Landry will meet privately with the commission's chairwoman to hear the government's position on its interim recommendations.

"The reason why there is an interim report is to allow for this kind of feedback and ... to allow for a public discussion of the path the boundaries committee is on," Dexter said.

"If they're off track, this is the time to tell them that."

MacNeil said she will consult with the members of the commission before commenting on what its next step is. But she said any meeting with Landry should be on the public record.

"Everything we do is for the public record," she said.

The protected ridings include Clare and Argyle, communities with large francophone populations on the South Shore, and Richmond, a riding in Cape Breton with a minority Acadian population.

The riding of Preston, which has a large number of black constituents, is located on the eastern outskirts of Halifax.

The commission has also recommended two new seats be added in Halifax and the overall number of seats in the legislature remain at 52.