Video (05:09) : U.S. senators questioned representatives of Facebook, Google and Twitter at a hearing Tuesday about Russian agents interfering with American politics and elections.

– Sen. Al Franken has some questions about Russia for Attorney General Jeff Sessions — about eight pages’ worth.

Franken fired off a lengthy letter to Sessions on Thursday, asking him to give his own account of interactions between the Trump campaign and Russian operatives. It followed the guilty plea earlier this week by a former Trump foreign policy adviser on charges of lying to federal agents about his contact with Russians.

Russia and the Trump campaign have been a flash point between the former Senate colleagues since Sessions’ confirmation hearing, when he responded to a question from the Minnesota Democrat with a claim that he hadn’t heard from any Russians during the campaign. Sessions later clarified that he had met several times with the Russian ambassador, in his role as a United States senator.

The two clashed again over the issue at an October Senate Judiciary hearing. Under questioning from Franken at that hearing, Sessions said he was not aware of any communications between Trump campaign surrogates and Russians, and that he did not believe any occurred.

“I don’t believe it happened,” Sessions said.

Franken wrote that this week’s revelations about former Trump aide George Papadopoulos belied those statements. Court documents indicate Papadopolous was present at a meeting with Sessions and Trump in which he discussed arranging a meeting between Trump and Russian President Vladimir Putin.

“You failed to tell the truth about your interactions with Russian operatives during the campaign,” Franken wrote Sessions on Thursday. “This is an alarming pattern in which you, the nation’s top law enforcement officer, apparently failed to tell the truth, under oath, about the Trump team’s contacts with agents of Russia — a hostile foreign power that interfered with the 2016 election.”

Franken asked Sessions to respond within the next two weeks to the questions raised this week. In page after page of bullet-pointed questions, Franken asked Sessions for his account of events described in Papadopoulos’ indictment documents, including e-mails and meetings where the young policy adviser tried repeatedly to set up meetings between Trump and Russian agents, including Putin.

“We must get to the bottom of what happened so that we can prevent it from happening again,” Franken wrote.

A Justice Department spokesman declined to comment.