One of President Trump’s senior economic officials has abruptly left the White House in the middle of the economic crisis caused by the coronavirus pandemic. He becomes the second senior White House economic official whose departure was announced this month.

Tomas J. Philipson, acting chairman of the White House Council of Economic Advisers, will leave his post by the end of June, White House spokesman Judd Deere said in an email. The announcement comes two days after Kevin Hassett, a senior White House economic official and Philipson’s predecessor as chair of the CEA, announced he would also be stepping down. Hassett was brought back to the administration this winter but is preparing to step away again.

“After 3 great years at CEA I am departing back to University Chicago soon that permitted an unusual extended 3 years of leave,” Philipson wrote on Twitter. “It’s been an honor and privilege to work for and with this President!”

The departures come at a critical time for the White House and the country. The U.S. economy plunged into a recession earlier this year because of the shutdowns caused by the coronavirus. More than 20 million jobs were lost in April. The economy has shown some signs of a very slow recovery, but now there are growing concerns about a surge of coronavirus cases in a number of states, including Florida, Texas, and Arizona, and officials are debating the next steps.

The White House and Congress approved nearly $3 trillion in emergency aid this year to try to blunt the economic impact, but they are torn over how to proceed. Losing two top economists in the midst of the crisis could push more of the analysis of future steps onto other advisers who don’t have the same background or expertise. Still, Trump isn’t known for relying on the guidance of economists as much as his own instincts.

Philipson was not as prominent an adviser as Hassett when he held the role, per several White House officials. During a recent Rose Garden ceremony, Trump called on Hassett to speak but Philipson was not brought to the lectern. Still, Philipson has been an outspoken supporter of President Trump on social media and has also defended the president’s decision not to wear a mask to protect against the virus, writing on Twitter that “there is no randomized evidence yet and blinding would be difficult.”

Philipson also feuded with Obama administration CEA chair Jason Furman on Twitter. After Furman criticized a chart circulated by Hassett that appeared to show coronavirus deaths plunging to zero by mid-May, Philipson attacked Furman. Furman had called the chart a low point for the CEA, and Philipson responded: “Comparing things to the data might have helped Furman when he advised the worst economic recovery in history.”

Philipson also attacked on Twitter the New York Times columnist Paul Krugman as a “political hack” and said Furman is the only CEA chair “without peer-reviewed scientific work and academic appointments — it shows.”

The tweets alarmed former officials with the CEA, which has historically given presidents sober policy analysis and has tried to avoid political infighting.

Philipson was not seen as having major pull with the president or a significant impact on the administration’s negotiations with Congress, according to interviews with multiple senior administration officials.

The White House Council of Economic Advisers, along with the Treasury Department and Office of Management and Budget, decided not to publish economic projections as part of the White House’s summer budget update. Those numbers were expected to be unflattering and show a stark economic decline because of the pandemic. The administration said last month it was not releasing those numbers because the uncertainty caused by the pandemic made the economic statistics highly volatile.

In addition to Philipson and Hassett, those who have announced their departure from the White House in recent months include: Andrew Olmem, special assistant to the president for economic policy and deputy director of the White House National Economic Council; Eric Ueland, who served as the White House director of legislative affairs and played a key role in negotiations with Congress over the stimulus; and Joe Grogan, director of the White House Domestic Policy Council.