Commerce Secretary Wilbur Ross has agreed to testify before Congress next month amid accusations he lied about his controversial decision to add a citizenship question to the 2020 census the last time he was under oath in front of Congress.

Democrats are eager to again press Ross, who is responsible for overseeing the U.S. Census Bureau. Since he last testified, new evidence emerged suggesting he misled members about the basis for adding the question. Also, earlier this month, a federal judge blocked the Trump administration from adding the question to the decennial survey, ruling the way it went about making the decision violated federal law. The plaintiffs in that suit sought to depose Ross to find out his motivations for adding the question, but the U.S. Supreme Court stepped in to block that from happening.

Critics say the question is unnecessary and adding it was a political decision intended to drive down the census response rate among minorities. Ross and the Trump administration say they added the question in response to a Justice Department request seeking better data for enforcing the Voting Rights Act.

Rep. Elijah Cummings (D-Md.), the chair of the House Committee on Oversight and Government Reform, said Ross has agreed to appear voluntarily on March 14 before his committee.

“Committee Members expect Secretary Ross to provide complete and truthful answers to a wide range of questions, including questions regarding the ongoing preparations for the census, the addition of a citizenship question, and other topics. The Committee also expects full compliance with all of our outstanding document requests prior to the hearing,” he said in a statement.

Sylvain Gaboury via Getty Images Commerce Secretary Wilbur Ross has agreed to appear before another congressional committee on March 14.

Last year, Ross testified before multiple congressional committees and said his decision to add the question was made “solely” in response to a Justice Department request to do so. He also said he was unaware of any discussion of the issue with the White House.

On March 20, Rep. Jose Serrano (D-N.Y.) asked Ross if anyone in the White House or Republican Party had directed him to add a citizenship question. Ross said he was responding “solely to the Department of Justice’s request.” Two days later, he told Rep. Judy Chu (D-Calif.) that DOJ “initiated” the request for a citizenship question on the census. Pressed by Sen. Patrick Leahy (D-Vt.) in May over DOJ’s reason for adding the request, Ross said, “The Justice Department is the one who made the request of us.” Rep. Grace Meng (D-N.Y.) asked Ross if Trump or anyone in the White House had discussed adding the citizenship question, and Ross said he was “unaware of any such” conversation.

But emails made public after his testimony showed Ross wanted to add the question long before DOJ made its request and that Commerce Department officials, acting under Ross’ instruction, worked with DOJ to initiate the request. He also said he discussed the matter with “senior administration officials,” which included Steve Bannon, a former top White House adviser.

In a December filing with the Supreme Court, Justice Department lawyers said Ross’ comments were being taken out of context and that he did not conceal that he had discussed the question with White House officials before the DOJ request.

U.S. District Judge Jesse Furman, who blocked the Trump administration from adding the question to the census earlier this month, wrote the “post hoc interpretations” were “unconvincing.”