As the impeachment enquiry into US President Donald Trump formally moved into its public phase, President on Friday lashed out at “crazy” and “corrupt” opponents probing potential abuse of presidential power.

A furious Trump took to the broadcaster to air along an occasionally incoherent list of grievances — against the FBI, his political adversaries, impeachment inquiry leaders, the “deep state,” and more.

“Frankly, I want a trial,” Trump told morning show, Fox and Friends.

The House Intelligence Committee has not formally concluded its role in the enquiry, possibly waiting for a court ruling on Monday that could empower members to force senior Trump aides to testify.

The increasing prospect of becoming only the third US president formally impeached, after Andrew Johnson and Bill Clinton, has riled the brash New York billionaire, and he fired off multiple attacks against rivals leading the effort.

His main Democratic nemesis in Congress, House Speaker Nancy Pelosi, is “crazy as a bedbug” for pressing a “scam” impeachment, he fumed.

Democrats argue that Trump’s demand that a foreign leader investigates his potential adversary in the 2020 presidential election is impeachable conduct.

Trump has said that he was merely pressing Ukraine to ramp up its anti-corruption efforts. But he also claims the Bidens were involved in corruption.

On Thursday, David Holmes, a staffer from the US Embassy in Ukraine, who also testified described a conversation he overheard between Trump and US Ambassador to the European Union Gordon Sondland, which occurred on July 26, a day after a Trump-Zelensky phone call that triggered an anonymous whistleblower complaint and the impeachment inquiry.

Last week, President Trump described the impeachment probe against him as “witch hunt”, saying he was “too busy” to watch it.

In October, President Trump opposed impeachment enquiry, saying that there should be no public hearings during the House of Representatives’ impeachment enquiry against him, and directed White House Chief of Staff Mick Mulvaney not to appear before the committees investigating Trump’s phone call to Ukraine.

After almost a month of calling for greater transparency in the enquiry, the White House changed its strategy this week by prohibiting several of its officials from even testifying behind closed doors before the lower house committees.

Late September, the impeachment inquiry, which House Speaker Nancy Pelosi initiated over a complaint by an anonymous whistleblower, is looking into White House’s alleged efforts to withhold military aid to have Ukraine investigate a Trump’s political rival, Joe Biden.