Brett Kavanaugh, the new supreme court justice, counts the Trump administration’s solicitor general, who will be arguing cases before the high court on behalf of the president, as a close professional friend, according to emails that offer new insights into an all-male dinner club that Kavanaugh used to attend.

Emails obtained by the Guardian show that Kavanaugh, who was narrowly confirmed to the supreme court earlier this month, participated in monthly evening cocktails and dinners from 2001 to 2003 with a group of men that included Noel Francisco, who now serves as the Trump administration’s solicitor general. It is not clear whether the dinners continued after Kavanaugh became a federal judge in 2006.

Other attendees included a lawyer who is now a top strategic adviser to Rupert Murdoch; the author of the George W Bush-era “torture memos” that were used to justify illegal interrogation techniques; and two lawyers who now frequently appear before the supreme court on behalf of corporate clients.

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The so-called “Eureka” dinners – named after the college that Ronald Reagan attended – were briefly raised in a written question that was submitted to Kavanaugh by senators following his initial confirmation hearing. Asked what the Eureka Club was, Kavanaugh said in a written response: “A group of friends sometimes gathered for dinner. The scheduling emails for those dinners would sometimes be titled ‘Eureka’.”

What Kavanaugh’s answer did not fully explain was that the dinners were attended by an elite group of men closely associated with the Federalist Society, the rightwing organization that has played a major role in vetting and choosing judicial appointments for Republican presidents since its founding in 1982.

While Kavanaugh has stated his desire to mentor and promote women to the top ranks of the legal profession, there is no evidence that any woman was ever invited to a Eureka dinner, based on the emails the Guardian obtained.

While it would not have been improper for Kavanaugh and other like-minded Bush administration officials to regularly meet for dinner and drinks at that time, new revelations about the identity of his circle of professional friends raise questions about how the close-knit relationships Kavanaugh forged with other lawyers might influence his rulings in the future.

Richard Painter, a critic of Donald Trump who served as the Bush administration’s ethics lawyer from 2005-2007, said senators should have sought more information about the Eureka dinners before Kavanaugh’s confirmation, especially if he continued to attend the regular dinners as a judge on the DC circuit court of appeals.

“For a judge to have regular meetings with certain lawyers is very problematic but apparently the question was never asked,” Painter said.

The Eureka emails seen by the Guardian cover a limited period while Kavanaugh worked for the White House under George W Bush.

Facebook Twitter Pinterest John Yoo, who wrote the George W Bush era ‘torture memos’, was a dinner companion of Brett Kavanaugh at the Eureka club. Photograph: Melissa Golden/Getty Images

They show that the dinner companions who Kavanaugh described as “friends” include Viet Dinh, who now serves as a senior legal adviser to Rupert Murdoch and is a godfather to Lachlan Murdoch’s child; John Yoo, who wrote the so-called “torture memos”; and Robert Coughlin, the former deputy chief of staff at the Department of Justice who pleaded guilty to a conflict of interest crime related to the Jack Abramoff lobbying scandal. Coughlin was disbarred but reinstated as a lawyer in 2016.

Paul Clement, a lawyer at the firm of Kirkland & Ellis who frequently appears before the supreme court, also attended.

The emails indicate that the men met on the first Monday of every month, usually reserving a table at Bobby Vans restaurant, though they appeared to prefer the Caucus Room, an upscale steakhouse. The dinners were often arranged by Adam Ciongoli, who served as an adviser to then-attorney general John Ashcroft and now works as general counsel of Campbell Soup. Ciongoli is also a member of the Federalist Society.

In one email, Ciongoli wrote: “Gentlemen, Next Monday is the first monday [sic] of July, and an opportunity for us to get back on schedule.” He signed the email: Ciongo.

Emails show that the events sometimes included unspecified “special guests”. Several attendees who were approached by the Guardian declined to comment. They did not dispute that judges were among the special guests who were invited. Eugene Scalia, the conservative lawyer and son of the late Antonin Scalia, the supreme court justice who is considered the ideological father of the Federalist Society, was also included on the Eureka emails. Scalia is a lawyer at Gibson Dunn in Washington whose specialty is labor law.

Asked about solicitor general Noel Francisco’s attendance at the meetings and his friendship with Kavanaugh, Sarah Isgur Flores, a spokeswoman for the Department of Justice, said: “We encourage judges and advocates to dine, meet and discuss issues of the day here. The SG is often colloquially called the 10th justice of the court … I would say that most SGs have had close relationships with justices including the ones they clerked for, which includes reunions, dinners and frequent calls.”

But Painter, the ethics lawyer, said the DoJ’s stance was problematic, because it did not emphasize that any litigant before the supreme court needed to be treated equally, and that the solicitor general, who is meant to defend the president’s legal position on any case, ought not to have special sway.

“That statement should have pointed out that there should never be ex parte communications,” Painter said, referring to communications about a case between a lawyer and a judge that occurs outside the presence of opposing counsel.

Alex Azar, who now serves as the secretary of health and human services, also attended the dinners. Azar has oversight of the Trump administration’s claimed effort to reunite parents with children who were separated from them under the White House’s “zero-tolerance” immigration policies. Azar also has oversight of the implementation of the Affordable Care Act, the healthcare law known as Obamacare. Both issues could come before the court.

Another attendee, according to emails, was Gregory Garre, who served as an assistant to the solicitor general during Bush’s first term and is now a partner at Latham & Watkins. Garre has argued 43 cases before the supreme court. In 2010, Kavanaugh ruled in favour of Garre’s client, an e-cigarrette maker called Sottera, in a case Garre argued before the DC court of appeals.