A Bayou St. John neighborhood organizing group, which has long denounced a developer’s push to convert the closed Morris F.X. Jeff Sr. Elementary School into apartments, is turning its ire on the city zoning ordinance that makes that revamp possible.

The comprehensive zoning ordinance should be amended, the group said at a news conference on Thursday, because parts of it are not consistent with the city’s master plan, a 16-chapter document voters authorized in 2008.

Similar skirmishes over whether the zoning ordinance and the master plan are contradictory have emerged repeatedly in recent months, and they are indicative of the controversy surrounding the law. Though it was approved in May as a way to set rules for the master plan’s guidelines, it was contentious from the outset, as a slew of last-minute additions sparked criticisms that the public had no say in the process.

Also at issue is whether the master plan should be seen as a general guide or an inflexible mandate. That debate has divided the council, with council members Stacy Head and Susan Guidry leaning toward a more hard-line interpretation, while LaToya Cantrell, James Gray and others see it as more of a guide.

Specifically, the Bayou St. John group is highlighting a zoning category that was included in the master plan but that organizers say is absent from the zoning ordinance: “residential pre-war low density.” That density calls for no more than 24 family units per acre, organizers Jenny Bagert and Shana Sassoon said.

But the zoning category for Morris F.X. Jeff — formerly the McDonogh 31 School — is “multifamily residential.” That designation allows up to 35 units per acre, Bagert said, which means developers could build up to 45 units on the Morris Jeff site, significantly more than they believe the master plan authorizes.

Density matters, Bagert said, because jamming more residents into one area creates more noise, less parking space and more traffic, which leads to a reduced quality of life.

“It could change the very fabric of our neighborhood and the reasons we invest in it,” Sassoon said.

Neighbors plan to submit a zoning text amendment that would create a new designation, again for a maximum density of 24 units. Such requests may be initiated by any property owner, and they must be vetted by the City Planning Commission and City Council.

In a statement Thursday, Guidry’s office said she supports residents submitting text amendments for city consideration.

In materials presented at the news conference, the group dubbed itself Neighbors for Responsible Development. But both Bagert and Sassoon also have been affiliated with Neighbors of McDonogh 31, which has long opposed CCNO Development’s plans for the school.

The company wants to transform the stately three-story school building and one-story cafeteria building into 34 apartments. It also wants to build single-family homes on four lots behind the cafeteria, according to a March development plan published on the Faubourg St. John Neighborhood Association’s website.

Those plans came after three years of discussion with the association, according to McDonogh 31 LLC, which is affiliated with CCNO. The Neighbors of McDonogh 31 group is a separate entity.

Two years into that conversation, the Neighbors of McDonogh 31 group raised objections, developers said in a statement Thursday. Developers also said they submitted several proposals to the Faubourg St. John Association and have deferred the project while those conversations progressed.

The firm added that it will continue to work with the “official neighborhood group,” the Faubourg St. John Association, and that it “respectfully opposes” any zoning changes that differ from what was discussed with the community, as well as changes that oppose the spirit of the master plan and the zoning ordinance, which “when read together do not arrive at the same conclusions presented by the Friends of McDonogh 31.”

A stalemate occurred when the developer wanted 34 units, but the Neighbors of McDonogh 31 pushed for 30 units, said Steve Mardon, president of the Faubourg St. John Neighborhood Association.

His group has stayed out of the dispute. “The neighborhood association has not taken a position, and hasn’t been asked to take a position at this point,” he said.

Presuming that the Neighbors group filed its zoning amendment application, as was the stated plan Thursday, it could be heard at the next Planning Commission meeting, scheduled for Dec. 8.

Not everyone is against or neutral toward the development and the zoning that permits it, if the actions of at least one passer-by Thursday are any indication. In a move perhaps indicative of controversy surrounding such issues, a truck driver asked residents why they had gathered and whether they were “pro-master plan.”

When neighbors said they were and asked him to join them, he abruptly replied: “No. We need the flexibility in this town,” before driving off.

Follow Jessica Williams on Twitter, @jwilliamsNOLA.