Doug Krizner: U.S. carmakers are taking to the streets today. GM, Ford and Chrysler have organized a rally in downtown Chicago. It's aimed at beating back congressional efforts to raise fuel economy standards. From the Marketplace Sustainability Desk, Sam Eaton reports.

Sam Eaton: Traditional lobbying tactics recently failed to stop a Senate proposal that would raise fuel economy standards by about 40 percent, so U.S. automakers are adopting a grassroots approach.

Today's rally kicks off a joint campaign with the United Autoworkers to build popular support for a more modest fuel economy proposal, one that automakers say wouldn't put them out of business.

David Friedman with the Union of Concerned Scientists calls it a desperate attempt to scare workers and the public into supporting their cause.

David Friedman: They're basically threatening autoworker jobs by saying they're going to close down plants.

A Chrysler spokesman says gains in fuel economy are needed, but they don't have to come at the expense of workers and consumers.

The rally will feature testimony from construction crews and kids sport teams about why they need large trucks and SUVs. Hundreds of autoworkers from nearby Ford and Chrysler plants are expected to attend.

I'm Sam Eaton for Marketplace.

Follow Sam Eaton at @eatonsam