As the impeachment inquiry against US President Donald Trump in the Ukraine scandal progresses one of the central figures of the issue, Energy Secretary Rick Perry has tendered his resignation on Thursday.

Perry who promoted business interest in the fossil fuel industry harming the environment, has been caught up in the impeachment probe engulfing the US president, is the latest departure of a senior administration figure. “Rick has done a fantastic job at Energy but it was time three years is a long time,” Trump said, speaking in Texas. “We already have his replacement.”

The announcement came a day after the publication of an interview in which Perry said that on Trump’s orders he had communicated with the president’s personal lawyer Rudy Giuliani over alleged corruption in Ukraine.

Trump administration’s efforts to pressure Ukrainian President Volodymyr Zelensky to dig up dirt on Hunter Biden, son of Trump’s 2020 rival, Joe Biden in an alleged quid pro quo scenario had compelled Speaker Nancy Pelosi to initiate an impeachment inquiry against the Republican leader.

Trump is now threatened with impeachment ahead of the 2020 US elections. House Democrats conducting the impeachment inquiry issued a subpoena to Perry last week, asking him to turn over documents related to his dealings with Ukraine by October 18.

Perry drove forward Trump’s “energy dominance” policy, which included boosting sales of US fossil fuels to Ukraine and other countries, and he oversaw a sharp rise in production of fossil fuels.

Trump said Perry had told him of his plans to resign months ago, and that he would leave office at the end of the year.

The New York Times reported that Trump had previously considered Perry for other senior positions, including chief of staff, due to his avoidance of personal scandals that had hit many of his colleagues.

Perry, who was nominated for the role in December 2016, was one of the longest-serving cabinet members in an administration marked by high turnover.

Perry became the scapegoat in the ongoing impeachment inquiry on October 4 when Trump reportedly told Republican House leaders that he’d only made the now-infamous July 25 phone call to Zelensky at Perry’s request.

Perry however has denied the allegations and said, “Not once, as God is my witness, not once was a Biden name — not the former vice president, not his son — ever mentioned.” Perry said about his visits to Ukraine during an appearance on the Christian Broadcasting Network on October 4,  “Corruption was talked about in the country but it was always a relatively vague term of, you know, the oligarchs and this and that and what have you.”