Trade associations representing farmers, retailers, and manufacturers are joining forces in a new multi-million-dollar campaign to oppose President Donald Trump's tariffs, in the latest attempt by U.S. business to stop an escalating trade war.

Groups lobbying for months to persuade the president that tariffs are the wrong approach have been largely ignored, as Trump slapped duties on billions of dollars of imports from steel to Chinese products. But a new coalition called Americans for Free Trade is joining Farmers for Free Trade to change the direction in Washington by highlighting stories of businesses, consumers, and farmers in the heartland negatively affected by the duties.

The groups are launching a campaign of more than $3 million, involving town hall-style events in key congressional districts ahead of the midterm elections, digital advertising, and other grassroots outreach to Congress and the administration. More than 80 coalition members are signing a letter to all members of Congress asking for support in fighting the duties and providing oversight on trade policy matters.