"This subpoena will be issued by the Committee on Oversight and Reform on Friday, October 4, 2019, under the Rules of the House of Representatives in the exercise of its oversight and legislative jurisdiction and after consultation with the Committee on Foreign Affairs and the Permanent Select Committee on Intelligence," Cummings said.
The congressional committees are investigating the degree to which Trump allegedly jeopardised US national security by pressing Ukraine to interfere with the 2020 presidential election and by withholding security assistance to Ukraine as well as any efforts to cover up these matters, Cummings said.
"I do not take this step lightly. Over the past several weeks, the committees tried several times to obtain voluntary compliance with our requests for documents, but the White House has refused to engage with - or even respond to - the committees," Cummings said.
The scandal, which resulted in impeachment proceedings against Donald Trump and a diplomatic rift with the Europeans for Ukraine, was prompted by a complaint from a whistleblower who claimed that Trump might have abused power as he urged Zelensky to investigate the business dealings of Hunter Biden, former Vice President Joe Biden's son, with a Ukrainian gas company during a call this July.
After the report emerged, House Democrats launched an impeachment inquiry against the US president, claiming that he had committed “high crimes and misdemeanours”. However, Republicans have rejected the allegations, stressing that Trump has not violated any law, adding that the case is an operation ahead of the 2020 election.
Trump, in his turn, has also denied the allegations calling them another attempt at a political witch hunt to reverse the outcome of the 2016 presidential election, and published the transcript of the telephone call with Zelensky.