At the centre of the investigation is whether President Donald Trump abused his power and jeopardised national security by withholding US military aid from Ukraine in exchange for an investigation into his political rival, Joe Biden.
Trump has repeatedly denied doing anything wrong, and the White House is refusing to cooperate; so what happens next? And what will be the impact on next year's elections?
Presenter: Folly Bah Thibault | Guests: Richard Goodstein - Political consultant for the Democratic Party and former adviser to President Bill Clinton; Jack Kingston - Republican Party member and former senior adviser to Donald Trump's 2016 presidential campaign; Scott Lucas - Professor of political science and international studies at the University of Birmingham