House Intelligence Committee Chairman Adam Schiff claimed that a quid pro quo agreement between President Trump and Ukrainian President Volodymyr Zelensky is not necessary for Trump’s request that the foreign government investigate former Vice President Joe Biden and his son Hunter Biden to be an impeachable offense.

Schiff, 59, has been one of the driving forces behind the impeachment inquiry that began last month after an unnamed CIA official filed a whistleblower complaint alleging wrongdoing by the president during his phone call with Zelensky. However, Schiff’s ties to the whisteblower have given political opponents, including Trump, ammunition to question his actions.