Washington ? A Republican congressman on Saturday urged Attorney General Alberto Gonzales to resign, citing what he said were Gonzales’ contradictory statements about his role in the firing of eight federal prosecutors.

“I trusted him before, but I can’t now,” said five-term Rep. Lee Terry, whose district includes Omaha, Neb.

Gonzales’ credibility took a blow this past week during testimony by his former chief of staff, Kyle Sampson, before the Senate Judiciary Committee. Sampson, who resigned March 12, said the attorney general was regularly briefed about plans to fire the prosecutors and was involved with discussions about “this process of asking certain U.S. attorneys to resign.”

Lawmakers impatient to hear Gonzales’ side of the story said the embattled attorney general needed to explain himself quickly or risk more damage to his department. Gonzales is to testify on Capitol Hill on April 17.

“My views were that this was Democrat posturing and a witch hunt,” Terry said. “My trust in him in that position has taken a hit because of these contradictory statements by him.”

Terry’s change of heart came on the first day of a two-week break for House members.

Gonzales on Friday sought to explain weeks of inconsistencies about how closely involved he had been in decisions to dismiss the U.S. attorneys. He said he had been aware his staff was drawing up plans for the firings but did not recall taking part in discussions over which people would actually be told to go.