BROOKLYN HEIGHTS, BROOKLYN — The controversial proposal to reconstruct part of the Brooklyn-Queens Expressway by closing down the beloved Brooklyn Heights Promenade most likely won't become a reality, the mayor's panel reviewing the plans announced.

The 16-person panel, created by Mayor Bill de Blasio to take a fresh look at the city's plans, announced in an update last week that the most unpopular of the options has "very little chance" of being approved. The proposal to close the Promenade for six years and build a temporary highway in its place was one of two the city's Department of Transportation had put forward last year, sparking uproar among the communities surrounding the 1.5-mile section of the highway.

Chair Carlo Scissura said during a presentation about the panel's work so far that the group had "serious concerns" about any encroachment on the Promenade and planned to look into ways to avoid it. "There may be a need for a temporary alternative route during what could be a six to ten-year construction period, but the alternatives proposed by the city Department of Transportation present very serious issues with very little chance of being approved," the presentation said. "Other alternatives should be explored."

The assessment of the DOT plan was one of several takeaways Scissura said the panel had made since it was first created in April. Since then, the panel has held 10 of its own meetings, toured the BQE, met with local community groups and visited Albany to ask elected officials to extend the original deadlines for the project. The panel plans to reveal its final report sometime this fall.

In the report, Scissura said the panel will lay out what members think should be the guiding principles for rebuilding the section of the highway, but might not comment specifically on the various alternative proposals that have been submitted by local groups or architects.

At least one idea, suggested by the Regional Plan Association, seems to have caught the attention of the panel. That plan recommends switching the BQE from six lanes to four based on various ways to reduce traffic on the expressway. Scissura said that one of the panel's takeaways is that looking at these traffic reduction options is a necessary part of the redesign.