A Yale classmate of Judge Brett Kavanaugh accused him of a “blatant mischaracterisation” of his drinking while in college, saying that he often saw Mr Kavanaugh “staggering from alcohol consumption.”

The classmate, Chad Ludington, who said he frequently socialised with Mr Kavanaugh as a student, said in a statement that the judge had been untruthful in testimony to the Senate Judiciary Committee when he had denied any possibility that he had ever blacked out from drinking.

Mr Ludington said that Mr Kavanaugh had played down “the degree and frequency” of his drinking, and that the judge had often become “belligerent and aggressive” while intoxicated. Other former classmates have made similar claims.

“It is truth that is at stake, and I believe that the ability to speak the truth, even when it does not reflect well upon oneself, is a paramount quality we seek in our nation’s most powerful judges,” Mr Ludington said, adding that he planned to “take my information to the FBI.”

Mr Ludington, a professor at North Carolina State University who appears to have made small political contributions to Democratic candidates, said to The New York Times that he had been told by the FBI’s Washington field office that he should go to the bureau’s North Carolina, office on Monday morning. He said he intended to do that, so he could “tell the full details of my story.”

It is illegal to lie to Congress. But it was unclear whether the FBI would add Mr Ludington’s accusations to the newly reopened background investigation into allegations of sexual misconduct against Mr Kavanaugh, which has been limited in scope and time by the White House and Senate Republicans.

The White House had no immediate comment about Mr Ludington’s accusations.

Even before Mr Ludington’s statement, Democrats in Washington reacted with anger Sunday as the narrow scope of the new FBI background inquiry became clear, warning that it threatened to become a sham.

Senator Mazie Hirono, a Hawaii Democrat on the Judiciary Committee, said on ABC’s “This Week” that any investigation that limits whom the FBI can interview and which leads agents can follow would be a “farce.”

Senator Amy Klobuchar, a Minnesota Democrat who is also on the committee, described what she said was micromanaging from the White House: “You can’t interview this person, you can’t look at this time period, you can only look at these people from one side of the street from when they were growing up.”

“I mean, come on,” she said on CNN’s “State of the Union.”

The White House agreed Friday to order the FBI to conduct a “limited” one-week supplemental background check of Mr Kavanaugh after a small number of Republicans joined Democrats in demanding an investigation into accusations of sexual misconduct.

White House officials have asked the FBI to interview four witnesses, a typical request in a background check.

No evidence has emerged that the White House has forbidden any investigative steps, and President Donald Trump has said he wants agents “to interview whoever they deem appropriate, at their discretion.”

In a tweet Sunday, Mr Trump accused Democrats of playing politics and said they would never be satisfied with any inquiry.

“Wow! Just starting to hear the Democrats, who are only thinking Obstruct and Delay, are starting to put out the word that the ‘time’ and ‘scope’ of FBI looking into Mr Kavanaugh and witnesses is not enough,” he wrote. “Hello! For them, it will never be enough.”

Democrats have cast the initial list of those to be interviewed as falling short of a full examination of the allegations. The four witnesses are Mark Judge and PJ Smyth, high school friends of Mr Kavanaugh; Leland Keyser, a high school friend of one of Mr Kavanaugh’s accusers, Christine Blasey Ford; and Deborah Ramirez, another of the judge’s accusers.

A lawyer for Ms Blasey, who riveted the nation Thursday as she recounted before the Judiciary Committee what she said was a rape attempt by a drunken Mr Kavanaugh when they were in high school, said Sunday that she had not been contacted by the FBI.

“We have not heard from the FBI despite repeated efforts to speak with them,” Debra S. Katz, the lawyer, said in a brief telephone interview Sunday morning.

Ms Blasey testified last week that she was willing to cooperate with authorities. Mr Kavanaugh has strenuously denied the accusations by Ms Blasey and other accusers.

The inquiry set in motion last week is aimed at resolving the fierce national debate over Mr Kavanaugh’s fitness to sit on the Supreme Court. But its abbreviated nature appears likely to disappoint his critics, who have insisted on a wide-ranging examination of his drinking and sexual habits as a high school and college student.

Even Democratic senators who had acknowledged that the background check would be limited said that they were disappointed.

In pictures: Chaos and fury at Brett Kavanaugh's confirmation hearing Show all 21 1 /21 In pictures: Chaos and fury at Brett Kavanaugh's confirmation hearing In pictures: Chaos and fury at Brett Kavanaugh's confirmation hearing WASHINGTON, DC - SEPTEMBER 04: Protesters disrupt the confirmation hearing for Supreme Court nominee Judge Brett Kavanaugh before the Senate Judiciary Committee in the Hart Senate Office Building on Capitol Hill September 4, 2018 in Washington, DC. Kavanaugh was nominated by President Donald Trump to fill the vacancy on the court left by retiring Associate Justice Anthony Kennedy. (Photo by Chip Somodevilla/Getty Images) Chip Somodevilla Getty Images In pictures: Chaos and fury at Brett Kavanaugh's confirmation hearing A member of Code Pink protests as US Supreme Court nominee Brett Kavanaugh arrives on the first day of his confirmation hearing in front of the US Senate on Capitol Hill in Washington DC, on September 4, 2018. - President Donald Trump's newest Supreme Court nominee Brett Kavanaugh is expected to face punishing questioning from Democrats this week over his endorsement of presidential immunity and his opposition to abortion. Some two dozen witnesses are lined up to argue for and against confirming Kavanaugh, who could swing the nine-member high court decidedly in conservatives' favor for years to come. Democrats have mobilized heavily to prevent his approval. (Photo by Brendan Smialowski / AFP)BRENDAN SMIALOWSKI/AFP/Getty Images BRENDAN SMIALOWSKI AFP/Getty Images In pictures: Chaos and fury at Brett Kavanaugh's confirmation hearing epa06996310 Circuit judge Brett Kavanaugh prepares to testify before his Senate confirmation hearing to be an Associate Justice of the Supreme Court of the United States in the Hart Senate Office Building in Washington, DC, USA, 04 September 2018. President Trump nominated Kavanaugh to fill the seat of retiring justice Anthony Kennedy. If confirmed, Kavanaugh would give conservatives a five-member majority in the high court. EPA/MICHAEL REYNOLDS MICHAEL REYNOLDS EPA In pictures: Chaos and fury at Brett Kavanaugh's confirmation hearing WASHINGTON, DC - SEPTEMBER 04: Protesters dressed in The Handmaid's Tale costume, protest outside the hearing room where Supreme Court nominee Judge Brett Kavanaugh will testify before the Senate Judiciary Committee during his Supreme Court confirmation hearing in the Hart Senate Office Building on Capitol Hill September 4, 2018 in Washington, DC. Kavanaugh was nominated by President Donald Trump to fill the vacancy on the court left by retiring Associate Justice Anthony Kennedy. (Photo by Win McNamee/Getty Images) Win McNamee Getty Images In pictures: Chaos and fury at Brett Kavanaugh's confirmation hearing A protester is removed during a hearing of the Senate Judiciary Committee on the nomination of Brett Kavanaugh to the US Supreme Court September 4, 2018 in Washington, DC. - President Donald Trump's newest Supreme Court nominee Brett Kavanaugh is expected to face punishing questioning from Democrats this week over his endorsement of presidential immunity and his opposition to abortion. Some two dozen witnesses are lined up to argue for and against confirming Kavanaugh, who could swing the nine-member high court decidedly in conservatives' favor for years to come. Democrats have mobilized heavily to prevent his approval. (Photo by Brendan Smialowski / AFP)BRENDAN SMIALOWSKI/AFP/Getty Images BRENDAN SMIALOWSKI AFP/Getty Images In pictures: Chaos and fury at Brett Kavanaugh's confirmation hearing A woman stands and voices her opposition to Supreme Court nominee Brett Kavanaugh, during a Senate Judiciary Committee confirmation hearing on his nomination for Supreme Court, on Capitol Hill, Tuesday, Sept. 4, 2018, in Washington. (AP Photo/Jacquelyn Martin) Jacquelyn Martin AP In pictures: Chaos and fury at Brett Kavanaugh's confirmation hearing WASHINGTON, DC - SEPTEMBER 04: Supreme Court nominee Judge Brett Kavanaugh arrives for testimony before the Senate Judiciary Committee during his Supreme Court confirmation hearing in the Hart Senate Office Building on Capitol Hill September 4, 2018 in Washington, DC. Kavanaugh was nominated by President Donald Trump to fill the vacancy on the court left by retiring Associate Justice Anthony Kennedy. (Photo by Win McNamee/Getty Images) Win McNamee Getty Images In pictures: Chaos and fury at Brett Kavanaugh's confirmation hearing WASHINGTON, DC - SEPTEMBER 04: Protesters disrupt the start of the Supreme Court nominee Judge Brett Kavanaugh's confirmation hearing before the Senate Judiciary Committee in the Hart Senate Office Building on Capitol Hill September 4, 2018 in Washington, DC. Kavanaugh was nominated by President Donald Trump to fill the vacancy on the court left by retiring Associate Justice Anthony Kennedy. (Photo by Mark Wilson/Getty Images) Mark Wilson Getty Images In pictures: Chaos and fury at Brett Kavanaugh's confirmation hearing A protestor is carried out by security as US Supreme Court nominee Brett Kavanaugh attends the first day of his confirmation hearing in front of the US Senate on Capitol Hill in Washington DC, on September 4, 2018. - President Donald Trump's newest Supreme Court nominee Brett Kavanaugh is expected to face punishing questioning from Democrats this week over his endorsement of presidential immunity and his opposition to abortion. Some two dozen witnesses are lined up to argue for and against confirming Kavanaugh, who could swing the nine-member high court decidedly in conservatives' favor for years to come. Democrats have mobilized heavily to prevent his approval. (Photo by Brendan Smialowski / AFP)BRENDAN SMIALOWSKI/AFP/Getty Images BRENDAN SMIALOWSKI AFP/Getty Images In pictures: Chaos and fury at Brett Kavanaugh's confirmation hearing A woman stands and voices her opposition to Supreme Court nominee Brett Kavanaugh, during a Senate Judiciary Committee confirmation hearing on his nomination for Supreme Court, on Capitol Hill, Tuesday, Sept. 4, 2018, in Washington.(AP Photo/Jacquelyn Martin) Jacquelyn Martin AP In pictures: Chaos and fury at Brett Kavanaugh's confirmation hearing A protestor is escorted out of the room as US Supreme Court nominee Brett Kavanaugh attends the first day of his confirmation hearing in front of the US Senate on Capitol Hill in Washington DC, on September 4, 2018. - President Donald Trump's newest Supreme Court nominee Brett Kavanaugh is expected to face punishing questioning from Democrats this week over his endorsement of presidential immunity and his opposition to abortion. Some two dozen witnesses are lined up to argue for and against confirming Kavanaugh, who could swing the nine-member high court decidedly in conservatives' favor for years to come. Democrats have mobilized heavily to prevent his approval. (Photo by Brendan Smialowski / AFP)BRENDAN SMIALOWSKI/AFP/Getty Images BRENDAN SMIALOWSKI AFP/Getty Images In pictures: Chaos and fury at Brett Kavanaugh's confirmation hearing U.S. Supreme Court nominee judge Brett Kavanaugh points to his daughters as his wife Ashley looks on before the start of his Senate Judiciary Committee confirmation hearing on Capitol Hill in Washington, U.S., September 4, 2018. REUTERS/Chris Wattie CHRIS WATTIE REUTERS In pictures: Chaos and fury at Brett Kavanaugh's confirmation hearing A woman protests as US Supreme Court nominee Brett Kavanaugh arrives on the first day of his confirmation hearing in front of the US Senate on Capitol Hill in Washington DC, on September 4, 2018. - President Donald Trump's newest Supreme Court nominee Brett Kavanaugh is expected to face punishing questioning from Democrats this week over his endorsement of presidential immunity and his opposition to abortion. Some two dozen witnesses are lined up to argue for and against confirming Kavanaugh, who could swing the nine-member high court decidedly in conservatives' favor for years to come. Democrats have mobilized heavily to prevent his approval. (Photo by Brendan Smialowski / AFP)BRENDAN SMIALOWSKI/AFP/Getty Images BRENDAN SMIALOWSKI AFP/Getty Images In pictures: Chaos and fury at Brett Kavanaugh's confirmation hearing U.S. Capitol police officer lead detained protesters out of the start of U.S. Supreme Court nominee Judge Brett Kavanaugh's Senate Judiciary Committee confirmation hearing on Capitol Hill in Washington, U.S., September 4, 2018. REUTERS/Joshua Roberts JOSHUA ROBERTS REUTERS In pictures: Chaos and fury at Brett Kavanaugh's confirmation hearing A protester is removed during a hearing of the Senate Judiciary Committee on the nomination of Brett Kavanaugh to the US Supreme Court September 4, 2018 in Washington, DC. - President Donald Trump's newest Supreme Court nominee Brett Kavanaugh is expected to face punishing questioning from Democrats this week over his endorsement of presidential immunity and his opposition to abortion. Some two dozen witnesses are lined up to argue for and against confirming Kavanaugh, who could swing the nine-member high court decidedly in conservatives' favor for years to come. Democrats have mobilized heavily to prevent his approval. (Photo by Brendan Smialowski / AFP)BRENDAN SMIALOWSKI/AFP/Getty Images BRENDAN SMIALOWSKI AFP/Getty Images In pictures: Chaos and fury at Brett Kavanaugh's confirmation hearing A protester is removed during a Senate Judiciary Committee confirmation hearing for U.S. Supreme Court nominee judge Brett Kavanaugh on Capitol Hill in Washington, U.S., September 4, 2018. REUTERS/Joshua Roberts JOSHUA ROBERTS REUTERS In pictures: Chaos and fury at Brett Kavanaugh's confirmation hearing A protester is removed during a hearing of the Senate Judiciary Committee on the nomination of Brett Kavanaugh to the US Supreme Court September 4, 2018 in Washington, DC. - President Donald Trump's newest Supreme Court nominee Brett Kavanaugh is expected to face punishing questioning from Democrats this week over his endorsement of presidential immunity and his opposition to abortion. Some two dozen witnesses are lined up to argue for and against confirming Kavanaugh, who could swing the nine-member high court decidedly in conservatives' favor for years to come. Democrats have mobilized heavily to prevent his approval. (Photo by Brendan Smialowski / AFP)BRENDAN SMIALOWSKI/AFP/Getty Images BRENDAN SMIALOWSKI AFP/Getty Images In pictures: Chaos and fury at Brett Kavanaugh's confirmation hearing epa06996576 A protester is removed as circuit judge Brett Kavanaugh appears before his Senate confirmation hearing to be an Associate Justice of the Supreme Court of the United States in the Hart Senate Office Building in Washington, DC, USA, 04 September 2018. President Trump nominated Kavanaugh to fill the seat of retiring justice Anthony Kennedy. If confirmed, Kavanaugh would give conservatives a five-member majority in the high court. EPA/JIM LO SCALZO JIM LO SCALZO EPA In pictures: Chaos and fury at Brett Kavanaugh's confirmation hearing epa06996814 Protesters inside the Hart Senate Office building under arrest as Brett Kavanaugh appears before his Senate confirmation hearing to be an Associate Justice of the Supreme Court of the United States in the Hart Senate Office Building in Washington, DC, USA, 04 September 2018. President Trump nominated Kavanaugh to fill the seat of retiring justice Anthony Kennedy. If confirmed, Kavanaugh would give conservatives a five-member majority in the high court. EPA/TASOS KATOPODIS TASOS KATOPODIS EPA In pictures: Chaos and fury at Brett Kavanaugh's confirmation hearing US Capitol Police arrest a protestor during the US Senate Judiciary Committee confirmation hearing for Judge Brett Kavanaugh to be an Associate Justice on the US Supreme Court, on Capitol Hill in Washington, DC, September 4, 2018. - President Donald Trump's newest Supreme Court nominee Brett Kavanaugh is expected to face punishing questioning from Democrats this week over his endorsement of presidential immunity and his opposition to abortion. Some two dozen witnesses are lined up to argue for and against confirming Kavanaugh, who could swing the nine-member high court decidedly in conservatives' favor for years to come. Democrats have mobilized heavily to prevent his approval. (Photo by SAUL LOEB / AFP)SAUL LOEB/AFP/Getty Images SAUL LOEB AFP/Getty Images In pictures: Chaos and fury at Brett Kavanaugh's confirmation hearing US Capitol Police arrest a protestor during the US Senate Judiciary Committee confirmation hearing for Judge Brett Kavanaugh to be an Associate Justice on the US Supreme Court, on Capitol Hill in Washington, DC, September 4, 2018. - President Donald Trump's newest Supreme Court nominee Brett Kavanaugh is expected to face punishing questioning from Democrats this week over his endorsement of presidential immunity and his opposition to abortion. (Photo by SAUL LOEB / AFP)SAUL LOEB/AFP/Getty Images SAUL LOEB AFP/Getty Images

Officials said FBI agents were not making the kind of broad efforts that journalists have engaged in over the last several weeks to talk to anyone who might have information about Mr Kavanaugh’s sexual conduct or drinking habits as a young man.

Instead, they said, the inquiry had been designed to examine the allegations of Ms Blasey, a California university professor, and the assertion by Ms Ramirez, a classmate of Mr Kavanaugh at Yale University, that he had exposed himself to her.

The process of interviewing the four witnesses could be completed by as soon as Monday. While agents are free to follow up if they find evidence of criminal activity, the rules for background checks require that agents ask the White House if they want to expand the scope of their investigation or interview other witnesses.

Left off the list for interviews are former classmates of Mr Kavanaugh who have publicly disputed his testimony about his drinking and partying while a high school student at Georgetown Preparatory School, an all-boys Catholic school in suburban Maryland, and later at Yale.

Sarah Huckabee Sanders, the White House press secretary, denied Sunday that the White House was playing any improper role in the process, saying that Don McGahn, the White House counsel, had “allowed the Senate to dictate” the terms of the investigation, and that Trump would stay out of it.

People familiar with the investigation said Republican senators had developed the list of four potential witnesses for the FBI to interview, and shared it with the White House.

“The Senate is dictating the terms,” Ms Sanders said on “Fox News Sunday.” “They laid out the request, and we’ve opened it up. And as you heard the president say, do what you need to do, the FBI, this is what they do and we are out of the way and letting them do exactly that.”