Not later than the sixth day of May, each borough president shall submit to the mayor and the council a response to the mayor's executive budget. Such response shall indicate which of the recommended appropriations submitted by the borough president pursuant to section two hundred forty-five, which were not included by the mayor in the executive budget, should be considered by the council for inclusion in the budget. Any appropriations recommended in this manner for inclusion in the budget shall be accompanied by recommendations for offsetting reductions in other appropriations within the borough. Any such increases or reductions must be stated separately and distinctly and refer each to a single object or purpose.