The top US diplomat in Ukraine, testifying on Wednesday in the first televised hearing of the impeachment inquiry against President Donald Trump, linked the president more directly to a pressure campaign on Ukraine to conduct investigations that would benefit him politically.

William Taylor was one of two career diplomats who testified before the US House of Representatives Intelligence Committee as a crucial new phase began in the impeachment inquiry that threatens Trump’s presidency even as he seeks re-election in 2020.

Both Taylor and George Kent testified about their concerns about pressure by Trump and allies to get Ukraine to investigate Democratic political rival Joe Biden in a dramatic hearing that pitted Democratic and Republican lawmakers against each other.

While the hearing turned contentious at times – including sniping between lawmakers – the low-key testimony given by the two witnesses may have fallen short of giving the Democrats the ammunition they need to advance their argument that Trump has committed misdeeds worthy of ousting him from office.

In a disclosure that drew attention, Taylor, acting ambassador to Ukraine, pointed to the Republican president’s keen interest in getting Ukraine to investigate Biden, a former vice president, and reiterated his understanding that $391 million in US security aid was withheld from Kiev unless it cooperated.

Taylor said a member of his staff overheard a July 26 phone call between Trump and Gordon Sondland, a former political donor appointed as a senior diplomat, in which Trump asked about those investigations and Sondland told him the Ukrainians were ready to proceed.

Following the call – which occurred a day after Trump had asked Ukraine’s president during a phone call to conduct the investigations – the staff member asked Sondland, the US ambassador to the European Union, what Trump thought about Ukraine, Taylor said.

“Ambassador Sondland responded that President Trump cares more about the investigations of Biden, which Giuliani was pressing for,” Taylor testified, referring to Trump’s personal lawyer, Rudy Giuliani.

Asked by Adam Schiff, the committee’s Democratic chairman, if that meant Trump cared more about the investigations than about Ukraine, Taylor said: “Yes, sir.”

At a White House news conference with Turkish President Tayyip Erdogan after the hearing ended, Trump said he knew”nothing” about the call with Sondland that Taylor said his aide overheard.

“It’s the first time I heard it,” said Trump, who has denied any wrongdoing.

David Holmes, a Taylor aide subpoenaed to testify behind closed doors on Friday in the impeachment inquiry, is the staffer who overheard the call that Sondland made to Trump from Ukraine, said a person familiar with the issue.

Republican lawmakers called Taylor’s account hearsay and noted Ukraine’s president has not said he felt pressured by Trump.

The focus of the inquiry is on the July 25 telephone call in which Trump asked Ukrainian President Volodymyr Zelenskiy to open a corruption investigation into Biden and his son Hunter, and into a discredited theory that Ukraine, not Russia, meddled in the 2016 US election. Hunter Biden had been a board member for a Ukrainian energy company called Burisma.