Updated Friday at 2:49 p.m. ET

Saddled with delays caused by the coronavirus pandemic and last-minute changes by the Trump administration, the first set of 2020 census results were not ready for release by Thursday's year-end deadline for numbers that determine representation in Congress and the Electoral College for the next decade.

A Census Bureau employee, who spoke on the condition of anonymity for fear of retaliation in the workplace, confirmed to NPR that the bureau is still trying to fix irregularities uncovered in this year's census records.

The employee told NPR that career officials at the agency are working toward Jan. 9 as an internal target date for completing the current stage of processing records before assessing when to begin the final steps in producing new state population counts used to apportion seats in the House of Representatives and electoral votes among the states.

"If we miss Jan. 9, it's hard to envision that we would get apportionment done before inauguration," the employee said.

Shortly after NPR published this report, the Census Bureau released a statement announcing plans to "deliver a complete and accurate state population count for apportionment in early 2021, as close to the statutory deadline as possible."

"The schedule for reporting this data is not static. Projected dates are fluid," the bureau said in the announcement. The Associated Press first reported the bureau's plans to announce a delay.

Under federal law, the commerce secretary, who oversees the bureau, is required to report to the president the latest state population totals within nine months of Census Day, which was April 1.

Since the Dec. 31 deadline was put in place by Congress in 1976, the bureau has never failed in delivering the first set of census numbers by the end of a census year. Before the bureau was established, the federal government did miss similar reporting deadlines in the 1800s, and Congress extended them afterward.

The final timing of the 2020 census results' release could undermine President Trump's efforts to make an unprecedented change to who is counted in key census numbers before leaving office. This month, the Supreme Court ruled it was too early for courts to weigh in on whether Trump can exclude unauthorized immigrants from numbers that the Constitution says must include the "whole number of persons in each state."

If the first census results are not ready until after Trump's term ends on Jan. 20, it would be President-elect Joe Biden, not Trump, who would get control of the numbers, which are ultimately handed off to Congress for certification.

Back in April, the Trump administration publicly acknowledged that because of COVID-19, there was a need for four-month extensions to the legal deadlines for census results, including the demographic data due to states by March 31, 2021 for the redrawing of voting districts.

But the administration made an about-face and stopped asking Congress for those extensions in July, right around the time Trump issued a presidential memorandum calling for unauthorized immigrants to be left out of census apportionment counts.

Now, lawmakers will likely have to deal with the fallout of the missed census deadline after the new Congress is in session beginning Jan. 3.

Sen. Brian Schatz, a Democrat from Hawaii who co-sponsored a bipartisan Senate bill in September to extend census deadlines, is planning to re-introduce the legislation in 2021, Schatz's communication director, Mike Inacay, tells NPR.

While the delay was long expected in a tumultuous year and there is no penalty specified by federal law for not reporting the first set of numbers on time, the moment is remarkable for the Census Bureau, which had been planning and working towards Dec. 31 for close to a decade.

"I can tell you that nowhere have I seen a greater adherence to statutorily mandated deadlines," says Edgar Chen, a former attorney in the Commerce Department's Office of the General Counsel who has also worked at the Justice and Treasury Departments.

Barry Robinson, a former chief counsel for economic affairs at the Commerce Department, recalls advising Commerce Secretary Wilbur Ross during an internal meeting in 2017 about the legal obligation to adhere to the provided timelines for the census. But Robinson says, especially in light of the pandemic, the government cannot prioritize meeting deadlines over the importance of producing a complete and accurate count.

"I'm the first to say that what I'm looking at now with the delays caused by the disruption of COVID-19, I think there is a very plausible and justifiable argument for a reasonable extension of time to allow the Census Bureau to fully complete its functions," Robinson says.

U.S. census historian Margo Andersonnotes that until shortly before the 1930 census, the federal government did not have legal deadlines for reporting results to the president or Congress, although census workers were instructed to turn in paper reports by set dates.

"This used to take months to get paper sent around the country so that a lot of times the deadlines would be missed simply because of more localized incidents of a natural disaster," says Anderson, author of The American Census: A Social History.

Anderson warns that the full implications of the bureau missing the first reporting deadline for the 2020 census may not be clear until later.

"We won't know whether the census is sort of up to snuff until the data start rolling out," Anderson says. "And then we may look back, realizing what was going on was much more significant. But we don't know yet."

Copyright 2021 NPR. To see more, visit https://www.npr.org.