Ald. Brian Hopkins (2) urged his colleagues on Wednesday to support a tax break for the lab building at 2017 N. Mendell St. over the objections of city planning officials. [Baker Development Corporation]

A City Council committee abruptly gaveled out Thursday before reaching a resolution on a tax incentive proposal that pitted a local alderman against city planning officials in the latest sign of strain between the council and Mayor Lori Lightfoot’s administration.