Detroit’s interim mayor, Kenneth Cockrel Jr., and businessman David Bing racked up more endorsements this week in advance of the May 5 special election to fill out the remainder of ex-Mayor Kwame Kilpatrick’s term.

Bing secured four major endorsements on Thursday, according to campaign spokeswoman Meagan Pitts, including the Laborers Local 1191, one of Michigan’s largest construction unions. Bing is also backed by the Detroit Firefighters Association, the Detroit EMS Technicians, and the Detroit Retired Police and Firefighters Association. The Detroit News reported that these groups represent 12,000 people though not all of which are Detroit voters as Detroit has no residency requirements for city workers.

Meanwhile, Cockrel got a big endorsement of his own on Thursday when the Democratic committee of the 14th Congressional District decided to support Cockrel for mayor. Cockrel had already secured endorsements from Detroit Police Officers Association, United Auto Workers and the Service Employees International Union. U.S. Rep. John Conyers represents the 14th Congressional District, but the congressman has not endorsed any candidate.

Thought each candidate has strong endorsements, Cockrel seems to be making greater progress with grassroots efforts garnering support from some of the largest democratic grassroots groups in Detroit including Michigan Democratic Future and the Young Democrats of Michigan, which is the local chapter of Young Democrats for America.