NDP Leader Dominic Cardy is facing criticism over his leadership. (CBC)

NDP Leader Dominic Cardy is facing questions about his leadership from within his own party as tensions remain over his acclamation as the party's leader and the future of the NDP.

Cardy took over the party in March when the only other contestant was disqualified, a decision that is still resonating within the party.

Nicole O'Byrne resigned from the party's provincial executive over the weekend because of her objections to the way the leadership race was handled.

O'Byrne said the leadership rules are silent on whether the party's electoral officer, who was overseeing the leadership contest, could actually acclaim Cardy without a full vote of the party membership.

The electoral officer's decision to acclaim Cardy as the leader cast doubt over his ability to control the party, O'Byrne said.

"The fact that the convention never happened means he's currently still just in that status of a nominated candidate for the leadership," O'Byrne said.

"So any decision he makes as the so-called leader right now is without authority."

'Any sort of grumblings or rumblings you hear are from a very small, small portion of party members.'— Matt Doherty, former NDP candidate

Instead, O'Byrne said the electoral officer should have simply declared Cardy the only candidate in the leadership race and allowed the party membership to acclaim him or not at the previously scheduled convention.

Cardy is defending the process that allowed him to takeover the NDP.

Cardy said because the rules are silent on how the electoral officer should deal with an acclamation, he said the official was allowed to declare him acclaimed.

Further, Cardy said the NDP holds leadership review votes at every convention, including the one slated to be held later this fall.

The internal tensions within the NDP comes as the party appears to be experiencing some momentum in the province.

While the party was again shut out of the legislature in the 2010 election, it saw its share of the popular vote double to 10.3 per cent.

And in the recent federal election, the NDP held its one seat in Acadie-Bathurst and finished second in a majority of the other ridings. The Liberals, meanwhile, also won a single federal seat and placed third in seven other ridings.

Party modernization

The NDP ran a different style of campaign in 2010. Former NDP leader Roger Duguay campaigned hard against the promises being made by the Liberals and Progressive Conservatives, saying they were not affordable.

The NDP also promised to ban future political donations by unions and corporations.

Shortly after the federal election, Cardy told CBC News the NDP and the Liberals should entertain talks over future co-operation.

While the NDP leader did not rule out a merger, he said there could be many different styles of co-operation that would allow the two parties to advance policies that they both support.

Matt Doherty, who ran for the NDP in Quispamsis in last fall's provincial election, said the controversy surrounding Cardy's leadership has nothing to do with how he became leader.

Instead, Doherty said, it's about opposition to Cardy's plan to modernize and moderate the party.

"Any sort of grumblings or rumblings you hear are from a very small, small portion of party members," Doherty said.

However, O'Byrne said Cardy's wish to take the party in a new direction makes it all the more important his leadership be approved by the membership.