U.S. President Barack Obama on Thursday, January 10 nominated White House chief of staff Jack Lew to be the next U.S. Treasury Secretary, tapping a former Citigroup executive likely to be grilled in confirmation hearings over his time on Wall Street as the U.S. economy careened toward disaster, RIA Novosti reported.

Lew served as a managing director at Citigroup from 2006 to 2009, taking a $945,000 bonus from the firm after it was rescued from bankruptcy thanks to a massive taxpayer bailout in 2008, according to financial disclosure forms he filed with the federal government.

His confirmation hearing will likely include questions about his time at the company, a spokesperson for U.S. Sen. Chuck Grassley, a ranking member of the U.S. Senate’s finance committee, told RIA Novosti on Thursday.

In his announcement of the nomination at the White House on Thursday, Obama was effusive in his praise for outgoing Treasury Secretary Timothy Geithner, crediting him with righting the nation’s economic course after assuming the post in 2009 with “the wreckage of our economy still smoldering and unstable.”

But Lew’s time at Citigroup has sparked concerns about a revolving door between Washington and Wall Street that many say paralyzes efforts to crack down on the financial industry’s excesses.

Lew has also downplayed the role of deregulation in the financial crisis, while Sanders and other Wall Street critics say deregulation was pivotal in the proliferation of exotic financial products that nearly cratered the U.S. economy.