House Judiciary Committee Chairman Jerry Nadler (D-NY) on Thursday issued a subpoena for former Trump campaign manager Corey Lewandowski and former White House official Rick Dearborn as part of the panel’s investigation into whether the president committed obstruction of justice and public corruption.

“Corey Lewandowski and Rick Dearborn were prominently featured in the Special Counsel’s description of President Trump’s efforts to obstruct justice by directing then-White House Counsel Don McGahn to fire the Special Counsel, and then by ordering him to lie about it,” Nadler said in a statement.

Nadler has asked both men to appear for public testimony before his committee on September 17th.

According to special counsel Robert Mueller’s report on now-debunked collusion between the 2016 Trump campaign and Russia, Trump directed Lewandowski to asked then-Attorney General Jeff Sessions to limit the scope of Mueller’s investigation. Lewandowski did not make the request of Sessions and instead asked Dearborn to contact Sessions.

“Dearborn also said that being asked to serve as a messenger to Sessions made him uncomfortable,” Mueller’s report states. “He recalled later telling Lewandowski that he had handled the situation, but he did not actually follow through with delivering the message to Sessions, and he did not keep a copy of the typewritten notes Lewandowski had given him.”

According to a source close to Lewandowski, the former Trump campaign manager is willing to testify before the panel, reports ABC News.

The development comes amid speculation that Lewandowski will announce a bid for the U.S. Senate in New Hampshire during President Donald Trump’s Thursday evening campaign rally in Manchester, New Hampshire.