Census Bureau officials appear to be moving toward wrapping up the process of counting all inhabitants of the United States a month earlier than planned as a result of direction from the Trump administration and Congress’ failure to agree on an extension, current and former bureau officials said.

The move comes as President Trump has intensified efforts to change how census data is used. A memorandum last week from the president said undocumented immigrants should not be counted for congressional apportionment, which legal experts say would be unconstitutional. Civil rights groups said the earlier deadline would also lead to an undercount of populations that are often harder to count, including minorities, undocumented immigrants and low-income families.

The Census Bureau had planned to continue knocking on doors, along with telephone and online efforts, to obtain population data until Oct. 31 — a date that was moved back earlier this year because the coronavirus pandemic disrupted the agency’s field operations.

Now, it appears that date could be moved forward to Sept. 30.

A current Census Bureau official, who spoke on the condition of anonymity to speak candidly, said the shorter window might allow the bureau to meet its statutory deadline of providing data to Congress and the president by the end of the year. But other bureau officials have already called into question whether that’s possible because of the pandemic.

As of Wednesday, only about 63 percent of all households had responded, the bureau said. Some census takers have reportedly quit, citing concerns about contracting the coronavirus.

“We are past the window of being able to get those counts by those dates at this point,” Albert Fontenot, associate director for decennial census programs, told reporters in July, referring to the Dec. 31 deadline to deliver census data to the president.

NPR, citing three people within the Census Bureau, was the first to report that the date to end field-knocking activities has been set for Sept. 30. Bureau spokesman Michael Cook, who neither confirmed nor denied that field operations would end earlier, said the bureau is attempting to meet its statutory obligations as they stand now.

“At the end of the day, we are still currently evaluating operations to enable the Census Bureau to provide the data in the most expeditious manner,” Cook said. “And when those plans have been finalized, we will make an announcement. That’s where we are.”

The Trump administration initially sought four months more to complete the decennial tally because of complications created by the current pandemic. In March, the bureau suspended many field activities.

By law, a census of the U.S. population must be delivered to the president by Dec. 31 of the census year.

Under the initial plan to resume and extend data collection, the bureau resumed field activities on June 1 and extended the data collection period from mid-August to Oct. 31.

The Democratic-controlled House voted to extend the Dec. 31 statutory deadline and set aside an additional $400 million for the census effort as part of the Heroes Act. A measure in the Republican-controlled Senate also proposed an additional $448 million but did not include an extension.

Earlier this week, congressional Democrats called the Census Bureau’s director, Steven Dillingham, to an emergency oversight hearing about President Trump’s directive to exclude undocumented immigrants from the apportionment of congressional representatives. Democrats also raised concerns that the administration had reversed itself on extending the count because of the pandemic, saying that holding to the original timeline would lead to an inaccurate and unfair count.

The Trump administration has repeatedly tried to change the way the decennial census is carried out and how its data is used.

Commerce Secretary Wilbur Ross announced in 2018 that the census would ask about citizenship status, sparking multiple lawsuits. Last summer, the Supreme Court struck down the question.

Then, Trump ordered federal agencies to share administrative records data on citizenship with the Commerce Department. Civil rights organizations have filed a lawsuit saying that order is discriminatory and violates the Administrative Procedure Act, the same law that challengers invoked against the citizenship question.

Last month, the administration added two high-level political appointees to the Census Bureau, eliciting criticism from Democrats in the House and Senate and raising concern that the new hires could attempt to influence the count. Both appointees reportedly have questioned why the bureau wants to focus on improving response rates in hard-to-count areas, which include low-income and minority communities.

Rep. Carolyn B. Maloney (D-N.Y.) said in a written statement that shortening the period for data collection was part of broad efforts by the administration “to unlawfully politicize the census.”

“Today’s report that the Bureau will now cut short field operations critical to counting immigrant and communities of color is deeply troubling,” Maloney said.

Civil rights organizations, which have already initiated legal challenges to Trump’s directive on excluding noncitizens from apportionment, said shutting down field activities in September would also distort the count.

“Trump is again seeking to destroy the integrity and accuracy of the census for partisan gain,” Vanita Gupta, president and CEO of the Leadership Conference on Civil and Human Rights, said in a written statement. She also called on Congress to extend the Census Bureau’s reporting deadline. “If his plan proceeds, the census won’t be a true portrait of America, and every state and community will have to live for ten years under the harm of an unfinished count.”