A conservative group is targeting House Republicans with a digital billboard campaign that is heavily critical of President Donald Trump .

In the new ads, Republicans for the Rule of Law calls out Trump for prohibiting key witnesses in the Ukraine scandal from testifying in the House impeachment inquiry against him.

The ads show Trump with a finger over his mouth to indicate that he wants silence. He appears next to Secretary of State Mike Pompeo, former National Security Adviser John Bolton, acting White House Chief of Staff Mick Mulvaney and Trumps personal lawyer, Rudy Giuliani, in the images.

All apart from Trump have tape placed over their mouths to keep them from speaking.

What Is Trump Hiding? ask the ads, which will be placed in the congressional districts of House Republicans, including Reps. Greg Walden (Ore.), Mac Thornberry (Texas), Fred Upton (Mich.) Brian Fitzpatrick (Penn.), Adam Kinzinger (Ill.) John Katko (N.Y.) and Martha Roby (Ala.).