WASHINGTON           -      Three constitutional law experts called by Democrats will testify on Wednesday that President Donald Trump’s actions concerning Ukraine represented impeachable offenses as the House of Representatives Judiciary Committee began proceedings expected to end in charges against Trump.

A fourth law professor, chosen by Republican lawmakers, said in prepared testimony that the impeachment inquiry lacked testimony from people with direct knowledge of the events and that current evidence did not show that Trump had committed “a clear criminal act,” according to written opening remarks prepared for the committee.

An impeachment inquiry launched by the Democratic-led House in September focuses on the Republican president’s request that Ukraine announce investigations that could harm Democratic political rival Joe Biden.

After more than two months of investigation, the committee will hold a hearing to examine whether Trump’s actions qualify as the “high crimes and misdemeanours” punishable by impeachment under the US Constitution. If the House approves articles of impeachment - formal charges - then Senate then would hold a trial on whether to remove Trump from office.

The committee held its first hearing a day after the three Democratic-led committees leading the inquiry issued a report accusing Trump of abusing his office in a bid to help secure his re-election in 2020. As a first step, the Judiciary Committee will seek insights from four law professors on what constitutes an impeachable offence and how Trump’s actions compare with those of two former presidents - Republican Richard Nixon, who resigned after the House launched the impeachment process, and Democrat Bill Clinton, who was impeached by the House but not removed by the Senate.

Wednesday’s hearing could offer plenty of political theatrics between Democrats and Trump’s Republican allies. The three professors called by Democrats made clear they believed Trump’s actions constituted impeachable offenses.

“The president’s conduct described by the testimony embodies the (Constitution’s) framers’ concern that a sitting president would corruptly abuse the powers of office to distort the outcome of a presidential election in his favour,” Harvard University law professor Noah Feldman said in his prepared testimony.

Pamela Karlan of Stanford University law school said Trump abused his power by demanding foreign involvement in a US election, adding that the president’s actions “struck at the very heart of what makes this country the ‘republic’ to which we pledge allegiance.”

University of North Carolina Professor Michael Gerhardt also said the president committed “several impeachable offenses.”

Gerhardt also appeared to admonish Republicans. “No member of this House should ever want his or her legacy to be having left unchecked a president’s assaults on our Constitution,” Gerhardt said. “If Congress fails to impeach here, then the impeachment process has lost all meaning, and, along with that, our Constitution’s carefully crafted safeguards against the establishment of a king on American soil. No one, not even the president, is beyond the reach of our Constitution and our laws,” Gerhardt added.

The focus of the inquiry is a July 25 telephone call in which Trump asked Ukrainian President Volodymyr Zelenskiy to open an investigation into Biden and his son Hunter Biden and into a discredited theory that Ukraine, not Russia, meddled in the 2016 US election. Hunter Biden had joined the board of Ukrainian energy company Burisma while his father was US vice president. Trump has accused the Biden’s of corruption without offering evidence. They have denied wrongdoing.

George Washington University Law School Professor Jonathan Turley, the only witness chosen by the Republicans, said the current evidence does not adequately support the Democrats’ allegations against Trump. Still, Turley admonished Trump over the call to Zelenskiy and said leveraging US military aid to investigate a political opponent “if proven, can be an impeachable offence.”

Democrats have accused Trump of abusing his power by withholding $391 million in security aid to Ukraine - a vulnerable US ally facing Russian aggression - as leverage to pressure Kiev into conducting investigations politically beneficial to Trump. The money - approved by the US Congress to help Ukraine combat Russia-backed separatists in the eastern part of the country - was provided to Ukraine in September only after the controversy had spilled into public view.