A top United States diplomat gave dramatic testimony Wednesday to the impeachment inquiry into President Donald Trump’s dealings with Ukraine, telling lawmakers his boss sought to use leverage to secure political favors.

Addressing the House of Representatives Intelligence Committee, Gordon Sondland, Washington’s envoy to the European Union, said Trump directed a “quid pro quo” scheme to push Ukraine to launch a probe into a political rival.

Testimony from Sondland, who has hitherto been viewed as an ally of the Republican president, came amid a fractious Democratic-led impeachment probe that could see Trump kicked out of the White House

Read more: Trump diplomat gives evidence that hurts president