PORTSMOUTH — City Councilor Chris Dwyer believes it could “take a very long time” to redesign the proposed redevelopment of the McIntyre Federal Building property if the Washington office of the National Park Service continues to insist the one-story post office wing can’t be demolished.

“It really suggests a redesign and a rethinking. It isn’t a matter of you just tinkering with it,” Dwyer said Thursday.

Her comments come after city officials were involved in a conference call Wednesday afternoon where NPS officials from its Washington office objected to the plan of the city's development partner Redgate/Kane to demolish part of the post office wing to build a new 5˝-story mixed-use building.

City officials previously worked with the NPS Philadelphia regional office, which had approved of the plan, according to Deputy City Manager Nancy Colbert Puff.

The City Council had hoped to approve an application for the redevelopment of the 2.1-acre property at its July 9 meeting so it could be sent to NPS.

The city has been working to receive the federal building property for free from the General Services Administration, which owns the property, via the Historic Monument Program, which NPS administers.

Dwyer acknowledged the City Council will be unable to meet the July 9 deadline due to the time it will take Redgate/Kane to come up with a new redevelopment plan.

“The worse thing would be we just have an empty federal building," Dwyer said. "It could sit like that for years. I fear that that could happen. That would be an awful thing to have right in the middle of such a vibrant area.”

Dwyer said the best-case scenario is for the NPS Washington office to come to the “realization that maybe the preservation of a one-story wing isn’t important as all the other things that had been planned on the site, including the public space.”

She believes it’s important for the public to stay involved in the process and not let their discouragement cause them to give up.

“The key thing for people to keep in mind is the McIntyre building and its attached one-story wing will be there no matter what,” Dwyer said. “This way we can have some say in what goes there.”

City officials canceled the portion of Wednesday night’s Historic District Commission meeting that dealt with the redevelopment plan. “It doesn’t make sense to move forward with the design as it stands now, giving what we just heard today,” Colbert Puff said Wednesday.

Colbert Puff could not be immediately reached Thursday afternoon to discuss the next step in the process of trying to redevelop the federal building property, which the city has been trying to gain control of for 14 years. Colbert Puff said last week that city officials hoped a post office would remain on the property but Redgate/Kane had proposed a postal kiosk instead.

Dwyer said city officials have been waiting for post office officials to reveal their intentions about whether they wanted to stay on the property since the beginning of the redevelopment process.

“Nancy has been pulling her hair out trying to get an answer from them,” Dwyer said Thursday.

She also stressed the NPS Washington office's belief that the post office wing must be preserved and where the post office should go are separate issues. “The post office can go anywhere on that site,” she said.

“Obviously, this came as a surprise to us,” Michael Kane, president and chief executive officer of the Kane Co., said Thursday. “We take the historic preservation of this incredibly seriously and we have been working very hard to work within the guidelines of the Historic Monument Program."

City officials and development team were “instructed to work with the Philadelphia office, which has oversight into this project,” rather than the D.C. office, Kane said. He added that city staff received that direction from NPS.

If the developers are forced to keep the post office wing intact, it will likely result in the loss of the proposed “great hall,” which would include a four-season indoor public space that could feature a public market.

“We literally engaged with the city to take their ideas and put them on paper," Kane said. "They wanted this big public realm space, this 12-month-a-year space that they could enjoy. This is going to seriously compromise that space.”

The NPS Washington office asked the development team to “come back with a new (plan) that will protect the post office wing and we’ve agreed to do that,” Kane said.

But he believes allowing the developers to take down a portion of the wing would benefit the site architecturally.

“The McIntyre standing there all by itself … it’s odd if there’s nothing to balance it," he said. "One of the things the new building did was balance the McIntyre so it didn’t stand out like it does right now."

The developers are trying to “react as quickly” as they can to come up with a new development plan, but Kane declined to estimate how long that would take.

He also addressed critics who said the site was too built up and claims that Redgate/Kane and the City Council didn’t do enough to prioritize the location of the post office.

“We have worked really, really hard to provide the maximum of public space, 45 percent of the property is in the public realm, and yet people who didn’t show up and participate in the design process are complaining,” Kane said.

The proposed redevelopment calls for four new mixed-use structures, two of which would stand 5˝ stories, along with several public plazas and Linden Way, which would give pedestrians a way to walk through the development.