WASHINGTON — Leading Democratic senators are renewing their calls for the Justice Department to review whether Rudy Giuliani is complying with a federal law requiring him to disclose his work on behalf of foreign governments, the latest sign of how the president’s personal lawyer is becoming a major focus of lawmakers.

In a letter to the Justice Department's national security division, the senators said the former New York mayor’s effort to work with the Ukrainian government in an investigation into former Vice President Joe Biden’s son “raises serious additional questions about the legality of his work as a foreign agent while also representing and working on behalf of the president regarding official U.S. policy.”

The letter lists four publicly reported accounts of Giuliani’s other interactions with foreign governments, including attending a pro-Russian conference in Armenia in October 2018; a meeting with the king of Bahrain in December 2018 that preceded the signing of a security consulting contract; and two appearances at conferences hosted by an Iranian group advocating regime change, MEK.

“These are just a handful of new and continued activities by Mr. Giuliani which appear to be paid by foreign entities and government with a desire to influence U.S. policy,” the senators wrote. “Like any other American, Mr. Giuliani has legal obligations to report his work on behalf of foreign clients, and the Department of Justice should not give him preferential treatment or exempt him from his obligation just because he is the president’s personal attorney.”

The Democratic senators who sent the letter were Dick Durbin of Illinois; Elizabeth Warren of Massachusetts; Tom Udall of New Mexico; Tammy Duckworth of Illinois; Sheldon Whitehouse of Rhode Island; Richard Blumenthal of Connecticut; and Jeff Merkley of Oregon.

They first raised concerns about whether Giuliani was in compliance with the Foreign Agent Registration Act, or FARA, more than a year ago, but say they received no response to their requests.

Separately Wednesday, Sen. Jeanne Shaheen, D-N.H., a member of the Foreign Relations Committee, called for Giuliani to testify before the panel under oath about his interactions with Ukrainian officials and whether he was acting, as he told Fox News Tuesday night, at the request of the State Department.

First-time filings related to FARA have spiked in recent years since high-profile Trump associates, including former national security adviser Michael Flynn and former Trump campaign chairman Paul Manafort, faced charges stemming from special counsel Robert Mueller’s probe related to alleged FARA violations