Top Senate Republican Chuck Grassley of Iowa came out against the House’s bipartisan antitrust bills targeted at Big Tech on Monday evening, dealing a blow to those who want to curb Silicon Valley’s influence through the legislation.

Grassley, the ranking member on the Senate Judiciary Committee, is in talks to write antitrust legislation of his own with Democratic Sen. Amy Klobuchar of Minnesota, the chairwoman of the committee in charge of regulating tech giants such as Facebook and Google.