ORLANDO, Fla. — A top advisory committee to the U.S. Census Bureau is urging the statistical agency to allow the once-a-decade head count of every U.S. resident to continue through October instead of finishing at the end of September, warning a shortened timeline could cause accuracy problems for the 2020 census.

The Census Scientific Advisory Committee issued their recommendation after a two-day virtual meeting late last week.

The recommendation comes as federal judges on opposite coasts this week hear arguments in two lawsuits from civil rights groups, cities and counties who have sued to stop the 2020 census from ending at the end of the month. The lawsuits say minority communities, including Latinos, Asian Americans, and non-U.S. citizens, stand to be undercounted if the census ends a month early.

A hearing in Maryland was being held Monday, and a hearing in San Jose, California, will take place Tuesday.

Government attorneys have argued that the census must finish by the end of September to meet a Dec. 31 deadline for turning over numbers used for deciding how many congressional seats each state gets in a process known as apportionment. Facing a disruption in operations because of the coronavirus pandemic, the Census Bureau had asked Congress for a deadline extension. The request passed the Democratic-controlled House, but the Republican-controlled Senate has failed to act on it.

As of last Saturday, 95% of households had been counted, according to the Census Bureau.

The statisticians, economists and demographers on the advisory committee said they were concerned about the shortened schedule for processing the data once it has been collected, from a typical five months in past decades to the planned three months this year. They recommended that the deadline for turning in the apportionment figures be extended through next April.

“Untested post data collection processing systems may fail in ways that the Census Bureau cannot foresee today," the committee said in a statement.