CHICAGO (CBS) — Some Chicago labor leaders announced their support for mayoral candidate Gery Chico Monday at a time when one of his rivals, Rahm Emanuel, has promised to hold public employees accountable to taxpayers.

It was a matter of timing and sensitivity, the union bosses say, in reference to Emanuel telling city workers to remember who they’re working for while many of them were working around the clock battling a blizzard.

“We are not the problem, we are the solution,” Jim Sweeney, president of Local 150, said at a spirited news conference with Chico. “Rahm Emanuel does not understand that.”

Emanuel has said in recent TV commercials that city employees should remember who they’re working for.

The tone of the ad drew jeers from Henry Bayer of AFSME Council 31.

“Certainly it was a mistake to attack the people who were cleaning streets, the people in the midst of that storm. While everybody else was running home, a lot of city workers were coming out,” Bayer said.

Emanuel, who was endorsed by Illinois Secretary of State Jesse White on Monday, says he was out, too, supporting those plowing the runways at O’Hare. He said his ad was anything but an attack.

“My life has been in public service, and I put myself in the position that we are beholden to the taxpayers and delivering for them a service that they are expecting,” he said.

The Chicago Tribune, in its endorsement of Emanuel over the weekend, said Chico is less likely to disrupt the status quo with public employees unions.

Chico disagreed that he’d be a pushover on labor issues.

“We’re gonna sit in a room and talk about it. That doesn’t mean we’re gonna go easy,” he said.

There is at least some evidence that rank-and-file union members may disagree with their leadership by favoring Emanuel over Chico. Organized labor could turn out to be the key in determining whether there is runoff following the Feb. 22 mayoral election.

Contributing: CBS 2 Political Producer Ed Marshall