Development sent shockwaves through both presidential campaigns and has left Clinton and her aides - including Huma Abedin reeling

He wrote to tell committee chairmen about development; then it emerged it was because of Huma Abedin emails on Anthony Weiner's laptop

directed' not to inform Congress - and Lynch never gave such an order

But then Comey challenged whether he was being '

Details of confrontation between Comey and Loretta Lynch, the attorney general emerge as White House backs him as man of '

An astonishing confrontation between the attorney-general and the FBI director over Hillary Clinton's emails was revealed Monday.

Sources told Reuters how James Comey, the FBI boss, challenged Loretta Lynch, the nation's most senior prosecutor, over whether she was directing him to keep the bombshell discovery of new, 'relevant' emails secret from Congress.

The development was revealed by the news agency hours after the White House went out of its way to back Comey as a man of 'integrity' and rubbish Hillary Clinton's attack on him.

It also slapped down claims by Harry Reid, the Democratic Senate leader, that Comey may have been breaking the Hatch act and influencing the election, saying the President did not believe he was doing such a thing.

SCROLL DOWN FOR VIDEO

Head to head: Loretta Lynch was challenged by James Comey on whether he was being ordered not to tell Congress about the Clinton email development

Source: The emails were found on a laptop seized from Anthony Weiner which had emails his estranged wife Huma Abedin had sent and received. She was off the campaign trail on Monday

The Comey-Lynch confrontation unfolded on Thursday, some time after Comey was fully briefed on the existence of the trove of emails uncovered by agents investigating Anthony Weiner's sexting of a 15-year-old girl.

Lynch made it known that she thought his decision violated department policy, a source familiar with the matter told Reuters on Monday.

As Comey and Lynch aides debated last Thursday whether alerting Congress about the emails would comply with longstanding Justice Department policy against announcing overt investigative steps that would influence an upcoming election, Comey asked whether he was being explicitly directed not to do so.

Lynch never gave Comey the order not to send the emails, a senior government official said.

Comey's letter on Friday notifying members of Congress that the Federal Bureau of Investigation had discovered new emails apparently pertinent to the Clinton server probe has upended the presidential race and given new hope to Republican candidate Donald Trump that he can make a comeback and win on November 8.

Lynch's office informed the FBI on Thursday that sending the letter conflicted with a memo containing official guidance that is sent to all Justice Department employees during presidential election years, according to the official.

The memo instructs employees to 'never select the timing of investigative steps... for the purpose of affecting any election.'

But the Justice Department made no effort to block the FBI from obtaining a search warrant to review the emails, which the agency received on Sunday. The department is working closely with the FBI on the case.

Assistant Attorney General Peter Kadzik told several members of Congress in letters on Monday that the Justice Department was dedicating 'all necessary resources' to work with the FBI on its examination of the newly discovered emails 'as expeditiously as possible.'

However, an official familiar with the FBI review said investigators could not predict how long the examination would take.

The senior White House official said the president does not believe that the Republican law enforcement official is looking to 'intentionally influence the outcome' of the presidential election, despite Hillary Clinton and Senate Democratic leader Harry Reid's claims that he is

Senator Harry Reid, the Democratic leader in the Senate, sent Comey a letter on Monday accusing the FBI of keeping 'explosive information' under wraps about ties between the Trump campaign and Russian officials.

Reid wrote to the FBI in August, requesting information about those ties, including alleged meetings between a Trump adviser and several high-ranking sanctioned individuals in Russia in July, according to a copy of the letter seen by Reuters.

The FBI acknowledged that it received the letter and said it had replied to Reid's office. An aide to Reid said he was not aware of any response from Comey to the letter.

Clinton has been using the campaign trail to attack Comey.

However the White House went out of its way to distance itself from Clinton's attack and slap down Reid.

Press Secretary Josh Earnest would neither 'defend nor criticize' the letter Comey sent to Congress on Friday.

Bombshell: This was the picture Weiner sent to a 15-year-old girl which prompted an FBI investigation

But the senior White House official said the president does not believe that the Republican law enforcement official is looking to 'intentionally influence the outcome' of the presidential election.

'The president’s assessment of his integrity and his character has not changed,' Earnest said at his daily briefing. 'The president doesn’t believe he’s secretly strategizing to benefit one candidate or one political party.'

The White House directed questions about the Hatch Act to the Office of Independent Counsel today as it walked a fine line between backing Comey and undercutting Democrats, including his preferred successor, who say the FBI director acted out of turn.

'These are tough questions, so it's a good thing that he's a man of integrity and character,' Earnest told reporters, saying that Comey is in a 'tough spot.'

Earnest was careful not to chastise Comey for the letter while implying that the building disagreed with the move that created panic within the president's party.

The Obama spokesman went on to say that the president continues to have confidence in Comey's ability to do his job, regardless of the criticism he's receiving from other Democrats.

'The president thinks very highly of Director Comey,' he stated, restating the Oval Office occupant's belief that FBI head is not meddling in the election.

Earnest also maintained that he had no prior knowledge that Comey planned to contact Congress because the White House has no involvement in the investigation.

Lynch's involvement in the latest development in the email saga came despite her recusing herself in July from making a decision on whether to prosecute Clinton or her aides.

Comey was instead delegated the decision after it emerged that she had a secret half-hour meeting with Bill Clinton when both their private planes were on the tarmac at the same airport.

The meeting, at Sky Harbor International Airport, Phoenix, Arizona, only became public because of a local television camera crew spotting her plane.