Second whistleblower comes forward over Trump-Ukraine phone call

A second whistleblower has come forward claiming to have first-hand knowledge of the phone call that triggered an impeachment inquiry into Donald Trump.

The lawyer representing the first whistleblower has told ABC News that he is now representing a second official from the US intelligence community.

Mark Zaid said this second individual has been interviewed by the head of the intelligence community's internal watchdog office but has not filed a complaint.

In a comment to Associated Press, Mr Zaid said the new whistleblower has "firsthand knowledge that supported" the original whistleblower.

He confirmed both officials are fully covered by law that protects whistleblowers and although his new client had spoken to the inspector general, the person had not talked with the congressional committees conducting the investigation.

Mr Trump is accused of pressuring his Ukrainian counterpart during a telephone call in July to investigate his political rival Joe Biden, the leading Democrat contender to face the president in next year's election.

In the call, Mr Trump discussed having President Volodymyr Zelenskiy help look into the Biden family's business dealings in the country.

The conversation came after the US withdrew hundreds of millions of dollars of military aid from Ukraine.

Mr Biden hit back at Mr Trump on Sunday, saying: "In my experience, asking a foreign government to manufacture lies about your domestic political opponent is not 'done all the time.'"

The first unnamed whistleblower filed a complaint in which they claimed US officials were so concerned about what Mr Trump had said that his administration tried to "lock down" the transcript of the conversation.

It later emerged the whistleblower was not present for the call and based the complaint on second-hand information.

Early on Monday morning, Mr Trump attacked House Speaker Nancy Pelosi over her involvement, saying that she should be "immediately impeached" for knowing about Adam Schiff's (senate intelligence committee chair) alleged meetings with the first whistleblower about his controversial phone call.

Mr Trump claims Mr Schiff has misled the US with his alleged actions, saying a speech he gave was a "ruthless con".

This second whistleblower claims to have been present, which could unravel much of Mr Trump's insistence that the content of the complaint is "totally inaccurate".

Mr Trump has denied putting pressure on Ukraine's leader and says the investigation is a politically motivated witch-hunt.