Manhattan District Attorney Alvin Bragg (D) slammed House Republican calls for him to testify in front of lawmakers as a move that will “hinder, disrupt and undermine” his office’s investigation into former President Trump.

“It is not appropriate for Congress to interfere in pending local investigations,” Bragg said on Twitter over the weekend. “This unprecedented inquiry by federal elected officials into an ongoing matter serves only to hinder, disrupt and undermine the legitimate work of our dedicated prosecutors.”

Bragg is investigating Trump in connection with hush money payments to adult film star Stormy Daniels ahead of the 2016 election. The probe made headlines when Trump said he expected to be arrested in the investigation last week; however, an arrest has yet to happen.

The alleged revelation from Trump sparked outrage among Republican lawmakers in Congress, some of whom immediately called for Bragg to testify at a congressional hearing.

Bragg rebuked Republican appeals to get him to voluntarily testify. Bragg’s statement on Twitter came in response to a letter from a number of Republican House committee chairs, who argue that any potential indictment of Trump is politically motivated and part of a left-wing scheme to smear the now-presidential candidate.

“Our Committees are conducting oversight of your reported effort to indict a former President of the United States and current declared candidate for that office,” the chairs, including Reps. Jim Jordan (R-Ohio), Bryan Steil (R-Wis.) and James Comer (R-Ky.), said in the letter to Bragg. “Notably, your reply letter did not dispute the central allegations at issue—that you, under political pressure from left-wing activists and former prosecutors in your office, are reportedly planning to use an alleged federal campaign finance violation, previously declined by federal prosecutors, as a vehicle to extend the statute of limitations on an otherwise misdemeanor offense and indict for the first time in history a former President of the United States.”

Bragg said the lawmakers’s requests to get him to testify were an “unlawful incursion” on his investigation.

The grand jury investigating Trump ultimately did not end up meeting last week after the former president’s claim that an indictment of him was imminent.