Officials with the civil rights division of the U.S. Department of Justice said in a court filing Monday they're troubled California officials did not act on a 2007 student census that found 20,000 English learner students had received no specialized instruction.

“California’s EL students cannot afford to wait any longer,” the filing by Acting Assistant Attorney General Jocelyn Samuels said.

The document was filed in support of a 2013 lawsuit by the American Civil Liberties Union against the state, claiming uneven English learner services are a violation of state law.

The US Dept. of Justice began investigating California's English learner monitoring in 2013.

State and federal law requires schools to give students who speak a language other than English at home specialized teaching to get them up to speed in academic English. The students in question make up less than 2 percent of the state's population of English learner students.

State officials have argued that the 20,000 figure means that the state is doing its job because most English learners are receiving services.

“When the state gets a report from its own districts that says that children within the district are not receiving instructional services the first thing the state needs to do is instantly investigate what’s going on,” countered ACLU chief counsel Mark Rosenbaum.

Federal officials said in the filing that the law gives schools flexibility but “does not provide states or districts the discretion to choose not to serve thousands of their EL students at all.”

The filing by federal officials “puts additional pressure on the state to say that it’s going to do the right thing in terms of assuring that all kids get equal educational opportunity,” Rosenbaum said.

The ACLU's lawsuit is set to go to trial on July 31.

State Superintendent of Public Instruction Tom Torlakson and the other defendants “do not agree with the assertions made in the pleading” said spokeswoman Pam Slater in a written statement.

“Once the USDOJ takes the time to fully review the extensive documentation submitted by the CDE over the past seven months," she added, "it will realize that the State takes seriously its obligation to monitor and ensure the provision of services to all English Learner Students.”