Composite image of Secretary of State Mike Pompeo and former New York City Mayor Rudy Giuliani (screengrabs)
On Saturday, longtime GOP strategist and Never Trump conservative Bill Kristol announced that the group "Republicans for the Rule of Law" will be airing an ad on Fox News Monday, putting pressure on Trump and Senate Republicans to allow testimony from the president's key allies in the impeachment trial.
Witnesses they are demanding testify include Trump's personal lawyer Rudy Giuliani, Secretary of State Mike Pompeo, White House chief of Staff Mick Mulvaney, and former National Security Adviser John Bolton.
In addition to the national Fox News ad spot, the ad has already begun airing in states represented by key GOP senators.
Watch below:
