WASHINGTON (Reuters) - The U.S. House Oversight Committee plans to vote next week on holding Attorney General William Barr and Commerce Secretary Wilbur Ross in contempt of Congress for stonewalling a probe into an alleged scheme to politicize the 2020 U.S. Census.

FILE PHOTO: T-shirts are displayed at a community activists and local government leaders event to mark the one-year-out launch of the 2020 Census efforts in Boston, Massachusetts, U.S., April 1, 2019. REUTERS/Brian Snyder

On Friday, the committee’s majority Democrats released a memo alleging that the White House “interfered directly and aggressively” with an attempt by the panel to interview Kris Kobach, a former Kansas Secretary of State, about a plan by President Donald Trump’s administration to add a question on citizenship to next year’s U.S. Census questionnaire.

“These aggressive efforts by the White House to block Mr. Kobach from cooperating with the Committee raise significant new questions about what the Trump Administration is concealing - and why,” the committee’s chairman, Democratic Representative Elijah Cummings, said in a statement.

The House of Representatives committee’s Democrats said they scheduled next week’s contempt vote after both Ross and Barr did not produce documents about the issue in response to a bipartisan subpoena the panel issued more than two months ago.

The White House had no immediate comment. Kobach did not immediately respond to a query sent to his political website.

A committee announcement said the contempt vote would initiate civil litigation to force compliance with its subpoena.

Oversight Committee Republicans criticized the Democrats’ moves, accusing Democrats of “cherry-picking facts.”

“Kris Kobach’s testimony shows that he was a peripheral and inconsequential player in the decision-making process and that the Department of Commerce did not rely on Kobach in making its decision. The Democrats also mischaracterized the White House’s involvement in the interview,” a Republican committee spokesman said.

In a memo providing details of a June 3 interview with Kobach, committee Democrats said that he limited his cooperation under White House orders, but did provide fresh information.

The committee said it interviewed Kobach in part to try to determine how the Trump administration devised its plan to question census respondents about their citizenship. The committee said Ross testified that he added the question “solely” at the request of the Justice Department.

However, the committee said documents showed that Ross “began a secret campaign” to add the citizenship question to the census questionnaire shortly after taking office and months before being asked to do so by the Justice Department.

The committee said documents and testimony also showed that discussions between Kobach and Ross were “orchestrated” by former presidential adviser Steve Bannon.

A Commerce Department spokesperson said in a statement that Ross testified truthfully before the panel. “It is clear that no matter how much the department cooperates and provides information in good faith, the committee will lie about the facts,” the statement said.

The committee said Kobach confirmed to its staffers that days after Trump’s inauguration, he met with top White House officials, including Bannon and Trump himself, to discuss adding the citizenship question to the census.

The committee said Kobach acknowledged raising the issue during the 2016 presidential campaign, during which he was an “informal” adviser to Trump.