Trump lawyer Joseph Tacopina said during TV interviews Friday he would “very aggressively” challenge the legal validity of the Manhattan grand jury indictment. Trump himself, on his social media platform, trained his ire about what he calls a “political persecution” on a new target: the judge expected to handle the case.

While Trump and his lawyers prepared for his defense, the prosecutor in his hush money case defended the grand jury investigation that propelled him toward trial, as congressional Republicans painted it all as politically motivated.

In a letter obtained by The Associated Press, Manhattan District Attorney Alvin Bragg told three Republican House committee chairs Friday that such claims are “misleading and meritless” and rebuffed congressional probing into the grand jury process – by law, a confidential one.

“We urge you to refrain from these inflammatory accusations, withdraw your demand for information, and let the criminal justice process proceed without unlawful political interference,” Bragg wrote to Reps. James Comer, Jim Jordan and Bryan Steil.

House Speaker Kevin McCarthy has vowed to use congressional oversight to probe Bragg. Steil, Jordan and Comer have asked Bragg’s office for grand jury testimony, documents and copies of any communications with the Justice Department.