The move comes after the Justice Department confirmed Wednesday that Sessions spoke twice previous year with Ambassador Sergey Kislyak while serving as a prominent supporter and adviser to Trump's presidential campaign. The Times also noted that this meeting came at just the time when the Obama administration was preparing to sanction Russian Federation for said interference. Schumer also bit back at the president, saying his meeting was public and challenged Trump to go under oath about his relationship to Russian Federation.
In Trump's first month in power, his national security adviser, Michael Flynn, was forced to resign after disclosures that he had been in frequent contact with Sergei Kislyak, the Russian ambassador to the United States, including the day that president Barack Obama expelled 35 Russian diplomats over Russia's hacking of the election. While Sessions has now admitted he met twice with the Russian ambassador past year, he said they did not have any such conversations about political campaigns.
Russian officials dispute this characterization.
Mr Sessions, a former senator just three weeks into his new job, was reported to have met Russia's ambassador to Washington, Mr Sergey Kislyak, during the election campaign.
The Washington Post reported that Sessions was the only member of the Senate Armed Services Committee to meet with Kislyak in 2016.
House Democratic leader Nancy Pelosi accused Mr Sessions of lying under oath during his Senate confirmation hearing. Sessions told reporters he had done nothing wrong by failing to disclose the contact with Kislyak.
And that Obama's campaign vigorously denied any contact with Russian officials before or after the election.
Collins, a Republican, championed Sessions' nomination as the nation's chief law enforcement officer, providing a glowing introduction to her Senate colleagues and disturbing those concerned about his stances on women's rights, protections for LGBTQ people, the legalization of marijuana, and minority voting rights.
Mr Trump declared his "total" confidence in Mr Sessions - while adding that he "wasn't aware" of contacts between Mr Kislyak and his Attorney-General, who was then a senator actively supporting Mr Trump's campaign.
Trump's first National Security Adviser Michael Flynn stepped down last month after it was reported that he had discussed US sanctions with Kislyak in December, and misled Vice President Mike Pence about the details.
The question is not merely whether Trump and his team met in public with Russian officials, but if they actively worked with the Russian government to support Russian interests and tried to cover it up.
Democrats went further, demanding that the attorney general resign and that a special prosecutor be appointed to probe the administration's Russian Federation links.
President Trump has been dogged by questions about his advisers' ties to Russian Federation since the campaign.
Trump had, in a statement on Thursday, said that the scandal plaguing his Attorney-General over contacts with Kislyak "is a witch-hunt" and blamed Democrats for blowing up the controversy for political reasons.
Cummings called Sessions' claim during his confirmation hearing that he did not have communications with the Russians "demonstrably false".
Sessions oversees the Justice Department and FBI, which have led investigations into alleged Russian meddling in the election and any links between Russia and Trump associates.
"In light of the letter received from Senators late this afternoon, the Attorney General will respond to their questions along with his amended testimony on Monday", Justice Department spokesman Peter Carr said in a statement.
Read the full report from The New York Times here. "When the (intelligence community) does that type of comprehensive review, it is standard practice that a significant amount of information would be compiled and documented".