(Axios) In a letter to lawmakers Sunday House Speaker Nancy Pelosi (D-Calif.) issued a warning about the Trump administrations continued efforts to block acting Director of National Intelligence Joseph Maguire from turning over a whistleblower complaint that reportedly involves the president. If the Administration persists in blocking this whistleblower from disclosing to Congress a serious possible breach of constitutional duties by the President they will be entering a grave new chapter of lawlessness which will take us into a whole new stage of investigation. Between the lines: Its likely that the new stage of investigation that Pelosi is referring to is impeachment. House Intelligence Chairman Adam Schiff (D-Calif.) who along with Pelosi has refrained from endorsing impeachment until theres enough public support said Sunday that the whistleblower controversy could leave Democrats with no other choice.