The head of the nation’s most powerful business lobbying group made clear Tuesday that blocking the Environmental Protection Agency’s greenhouse gas regulations is a key part of his agenda.

U.S. Chamber of Commerce President Tom Donohue attacked EPA in his annual “State of American Business” speech Tuesday morning. He called the emissions rules, which have begun the phasing-in stage, part of a multi-front “regulatory tsunami” by the Obama administration.

“We will … continue our legal and legislative efforts to stop the EPA from misapplying environmental laws in order to unilaterally regulate greenhouse gases,” Donohue said in his prepared remarks.