Todd Blanche’s nomination to officially become the U.S. Attorney General faces new uncertainty after a key Republican senator said he still wanted written guarantees before moving forward.

Republican Sen. John Cornyn said the Justice Department had not followed up on his demand to formally eliminate the so-called anti-weaponization fund.

Blanche maintained that the fund was no longer active. However, Cornyn and Sen. Thom Tillis reportedly want written assurances before voting to advance Blanche’s confirmation.

The Judiciary Committee was scheduled to vote on Blanche’s nomination on Thursday.