Story highlights Jeff Sessions will testify next week before a subcommittee of the Senate appropriations committee

Former FBI director James Comey testified before the Senate intelligence committee Tuesday

(CNN) The series of dramatic congressional hearings will continue Tuesday, when embattled Attorney General Jeff Sessions takes the stand.

The Senate appropriations subcommittee hearing is billed as a discussion on the Justice Department budget, but Democrats say they will use the opportunity to grill their former Senate colleague about his alleged contacts with Russians and the controversial firing of former FBI Directory James Comey, among other hot-button issues.

"I have sought for months to clarify Attorney General Sessions' contacts with Russian officials following his false testimony in response to questions from me and from (Sen. Al) Franken. We wrote to the FBI requesting that they investigate such matters," said Sen. Patrick Leahy, D-Vermont, in a statement Thursday.

"I am also deeply concerned about the attorney general's role in firing Director Comey in light of his recusal from the Russia investigation."

Last week, Leahy and Franken, a Democrat from Minnesota, said Sessions should resign if he misled Congress about his contacts with Russians