The political network backed by the Koch brothers is launching a multiyear, multimillion-dollar campaign to oppose President Trump’s push to slap billions of dollars in tariffs on imports from around the world.

The announcement Monday by three groups funded by the billionaire industrialists comes days after the Trump administration imposed new levies on steel and aluminum imports from the European Union, Canada and Mexico and threatened to press ahead with $50 billion in tariffs on Chinese products.

The tariff decision elicited outcries from allies abroad and domestic business groups — but arguably none more influential among conservatives than the Koch network.

The campaign will include spending on “paid media, activist education and grassroots mobilization, lobbying and policy analysis,” the groups said in a release.

“Tariffs and other trade barriers make us poorer. They raise prices for those who can least afford it. That’s why this issue is so important,” Freedom Partners Executive Vice President James Davis said in a statement. “This announcement is a demonstration of our long-term commitment to advance common-sense trade policies that will ensure America’s brightest days are ahead, and to directly confront the protectionist ideas that would hold us back.”

Americans for Prosperity and the Libre Initiative are the other two Koch-sponsored organizations joining the campaign.