Ashlee Rezin/Sun-Times Mayor Lori Lightfoot was urged Thursday to stop using the pandemic as an “excuse” for a police hiring slowdown and start filling a slew of police vacancies that have forced officers to work excessive amounts of overtime. Former mayoral challenger Paul Vallas served as a lead negotiator for the Fraternal Order of Police. He helped to deliver the tentative, eight-year contract that ended the longest labor stalemate in Chicago history. On Thursday, Vallas pegged the number of vacancies among rank-and-file officers at 1,000. That’s notable, since Lightfoot’s $12.8 billion 2021 budget eliminated 614 police vacancies, shrinking the Chicago Police Department by attrition.