The young Russian operative called her strategy the “Diplomacy Project,” an elaborate, multiyear scheme to infiltrate the conservative movement in the United States in hopes of cementing bonds to benefit the Kremlin.

Maria Butina laid out the proposal in March 2015 and then pursued her plan over the next two years, traveling to conferences to schmooze Republican presidential candidates. She established close ties to top officials in the National Rifle Association. She hosted “friendship dinners” with wealthy Americans. And she organized a Russian delegation to attend the influential National Prayer Breakfast in Washington.

Much of Butina’s work has been reported over the past year as part of a broader campaign by Moscow to influence U.S. elections — but new details are included in documents obtained by The Washington Post that will be filed in court Thursday, when Butina is expected to admit for the first time that her activities were part of a concerted endeavor, coordinated with a top Russian official with the express intent of establishing unofficial lines of communication with Americans who could influence U.S. politics.

The documents show Butina plans to admit she worked at the direction of a former senator who was deputy governor of the Russian central bank. That description matches Alexander Torshin, who was subjected to economic sanctions by the U.S. government earlier this year and resigned his bank position in November.

Butina is being prosecuted by the U.S. attorney’s office in Washington, not special counsel Robert S. Mueller III. But with a plea, she will become the first Russian national convicted of working to influence U.S. policy around the time of the 2016 election.

Butina’s plea will not be final until it is entered in court and accepted by a judge. A hearing is scheduled for Thursday morning.

Details of Butina’s plea agreement, signed Saturday, were first reported by ABC News.

Russian gun rights activist Maria Butina developed bonds with conservative leaders during the 2016 campaign - culminating in outreach to then-candidate Trump. (The Washington Post)

Butina will agree she briefed Torshin on her effort to pierce the conservative movement from her start in 2015 to her continuing activity as she moved to Washington to enroll as a graduate student at American University in 2016. She at times asked whether the Russian government would be ready to meet her contacts. Torshin, in turn, consulted about her work with his superiors at the government-run bank and the Ministry of Foreign Affairs, prosecutors said.

Steven L. Hall, who managed Russian operations at the CIA for 30 years, said the Butina case shows the lengths to which the Russians will go to influence and divide the United States. Butina did not appear to engage in traditional espionage, he said, but instead employed a variety of more informal tools to advance Russian interests.

“Butina is not a staff officer of any Russian military or intelligence agency. But she is someone the government chose to use as they sought different ways to attack the U.S. social and political system,” he said.

Butina, 30, is expected to tell a federal judge she worked hand-in-hand with an American Republican operative in her attempts to advance Russian interests, including in drafting the “Description of the Diplomacy Project” in 2015 that launched her efforts. He has been previously identified as Paul Erickson, a South Dakota consultant who has been active in Republican causes for years and who managed the 1992 presidential campaign of conservative pundit Pat Buchanan. Butina and Erickson have been romantically involved since they met while Erickson was visiting Moscow in 2013, her lawyer has said.

People familiar with the case have said Erickson earlier this year received a letter from federal prosecutors informing him he was also considered a target of their investigation, a letter first reported by the Daily Beast. He did not respond to requests for comment Tuesday.

Butina’s work came against the backdrop of what the U.S. intelligence community has said was a sweeping Russian government effort to help Donald Trump win the presidency, including by hacking and distributing emails stolen from Democrats.

The charge to which Butina is set to plead requires foreigners working for their government to register with the Justice Department, and it has been used in the past to prosecute foreign intelligence officers. There is no suggestion in the documents that Butina was employed by the Russian intelligence services, but violations of the law are considered more serious than a separate law that requires registration by paid lobbyists for foreign entities.

Butina crossed paths with Trump, including in July 2015, when she asked the newly declared Republican candidate about Russia and sanctions at a public event in Las Vegas. “We get along with Putin,” Trump told Butina, referring to the Russian president. “I don’t think you’d need the sanctions.”

Erickson also tried to get Trump to meet Torshin when both attended the NRA’s convention in May 2016, referring to Torshin as “Putin’s emissary” in an email to a campaign official. The campaign declined a meeting, but documents provided to Congress show Butina and Torshin met briefly during the event with Donald Trump Jr., one of the president’s sons.

Butina has been jailed since her arrest in July, and in her plea deal, she agreed to remain behind bars until her sentencing. However, in exchange for her guilty plea, prosecutors agreed to drop a second charge of acting as a foreign agent, the documents show. A judge will determine her sentence, but the deal means she could be released from jail and deported to Russia in coming months.

In Russia, where government leaders have insisted Butina was wrongly accused, word of her deal was greeted with questions about whether she was switching sides.

“This woman risks 15 years in jail. And for what?” President Vladi­mir Putin asked Tuesday at a meeting of a Kremlin council on human rights in Moscow. “I asked all the heads of our intelligence services what is happening, ‘Who is she?’ No one knows a thing about her.”

Her father, Valery Butin, told a pro-Kremlin newspaper that she had “not committed anything.”

“The only thing she might agree with is that she should have registered as a foreign agent,” he said.

In the “Diplomacy Project,” Butina suggested using unofficial channels to influence U.S. foreign policy because the U.S. government had grown too unwilling to compromise.

In particular, Butina predicted a Republican would probably win the presidential election and said she could help sway GOP opinion through ties she had built with the NRA.

Butina had founded a gun rights group in Russia and served as an interpreter for Torshin, a lifetime member of the NRA, as he attended its annual conventions. That role gave her access to conservatives intrigued by the idea of the Siberian-born self-made activist agitating for expanded gun rights in Putin’s restrictive Russia.

Butina and Torshin invited NRA leaders to Moscow in December 2015, a delegation that included Milwaukee County Sheriff David Clarke andDavid Keene, a former NRA president and past head of the powerful American Conservative Union. Documents reviewed previously by The Post show the group met with Russian Foreign Minister Sergei Lavrov.

The recent legal documents show Butina perceived the trip as a way to advance her political goals. Before the U.S. group arrived, she stressed to Torshin the importance of setting up meetings with top Russian politicians. After it ended, she sent Torshin a message: “We should let them express their gratitude now, we will put pressure on them quietly later.”

Butina’s efforts also included organizing “friendship dinners” for wealthy and influential Americans to discuss U.S.-Russia relations, ensuring Torshin kept tabs on the guests. “A wealthy and well-connected U.S. person,” who received assistance from Butina, helped organize the dinners, the plea agreement says.

Butina’s ongoing efforts after she enrolled at American University included organizing a Russian delegation to attend the 2017 National Prayer Breakfast in Washington, an event that annually draws a large number of U.S. conservatives to the capital and last year was addressed by Trump.

According to the documents, Erickson later emailed another person and copied Butina: “Reaction to the delegation’s presence in America will be relayed DIRECTLY” to Putin and to Lavrov.

Amie Ferris-Rotman and Anton Troianovski in Moscow and Spencer S. Hsu in Washington contributed to this report.