Originally Published: 26 APR 23 14:08 ET

By Paula Reid, Jeremy Herb, Katelyn Polantz and Zachary Cohen, CNN

(CNN) -- Two of Donald Trump's defense lawyers now believe that classified briefings of phone calls with foreign leaders were among "all manner of documents" in 15 boxes that Trump returned to the National Archives a year after he left the presidency, according to a new letter his lawyers sent to Congress.

This organization of the materials "indicates that the White House staff simply swept all documents from the President's desk and other areas into boxes, where they have resided ever since," the two lawyers, Timothy Parlatore and Jim Trusty, wrote to the GOP chair of the House Intelligence Committee on Wednesday.

Their characterization not only reveals new details about the documents but also comes as part of a broadside against the Justice Department's investigation into Trump over the classified documents that lays out talking points for Republicans as they try to portray the ongoing probe as politically motivated.

The lawyers urge Republicans to tell the Justice Department to "stand down," even as special counsel Jack Smith's probe has shown signs of nearing its end and even though Congress doesn't have the power to control DOJ criminal investigations.

Parlatore and Trusty say they reviewed the 15 boxes earlier this year that are now part of the Justice Department's investigation. They saw placeholder pages where classified documents were removed by the National Archives, according to the letter.

"The vast majority of the placeholder inserts refer to briefings for phone calls with foreign leaders that were located near the schedule for those calls," the lawyers wrote.

The 15 boxes were turned over to the Archives in January 2022. The FBI seized more boxes in August 2022 during a court-authorized search that found more than 100 classified documents, including 18 at the highest "top secret" classification level. Trump's own legal team later found more classified materials in a search other locations.

The Justice Department has never said exactly what was in the classified material found in Trump's possession after the presidency. Trump's lawyers say in their letter that the Justice Department has refused to tell them whether any of the documents remain classified.

It's not clear why at this point in the special counsel's investigation that the Trump legal team was given access to the boxes turned over to the National Archives to look through them.

Wednesday's letter was sent to House Intelligence Chairman Mike Turner, and it represents Trump's legal team seeking a political lifeline by asking Congress tell the Justice Department to step aside because they believe the intelligence community should conduct the investigation into what happened with the classified documents.

"DOJ should be ordered to stand down, and the intelligence community should instead conduct an appropriate investigation and provide a full report to this Committee, as well as your counterparts in the Senate," the lawyers wrote to Turner.

"This is indicative of the staff's packing processes and not any criminal intent by President Trump," the lawyers argued.

The lawyers also pointed to classified documents since discovered at the residences and offices of President Joe Biden and former Vice President Mike Pence.

"As demonstrated by the discovery of documents with classification markings in the homes of President Trump, President Biden, and Vice President Pence, deficient document handling and storage procedures are not limited to any individual, administration, or political party," the lawyers wrote.

The intelligence community said in August following the FBI search of Mar-a-Lago that it was conducting its own damage assessment of the classified documents that had been retrieved.

Earlier this month, intelligence leaders in Congress were provided access to some of the classified documents that had been taken from the residences and offices of Trump, Biden and Pence so that Congress could do its own review.

Trump's legal team did not send a similar letter to the Democratic-controlled Senate Intelligence Committee. Trump's allies have for years assailed the various probes into the former president, yet even his former Attorney General Bill Barr has said the classified documents investigation puts the former president in serious legal jeopardy.

In a February interview with CNN, Parlatore signaled Trump's legal strategy, saying that DOJ should be "benched" on matters related to classified material and it should be left up to the Office of the Director of National Intelligence to conduct an administrative review of the White House's procedure for handling such documents at the end of each presidency.

In Wednesday's letter, Trump's lawyers criticized the Justice Department's handling of the case before the search of Mar-a-Lago, arguing that federal investigators put Trump on the defensive by issuing a grand jury subpoena instead of working cooperatively with Trump.

The letter also tried to defend a certification made by one of Trump's attorneys last year following the subpoena. In June 2022, the lawyer, Christina Bobb, signed a certification that Trump had complied with the subpoena by turning over the classified documents in his possession.

"Ultimately, President Trump's legal team complied with DOJ's demands, performing as diligent a search as they could by Mr. (Jay) Bratt's arbitrary deadline, and submitted a certification that affirmed the same," the lawyers wrote in Wednesday's letter.

"To be clear, the certification stated that a diligent search was conducted, and all responsive documents found were provided — not that the search turned up all possible materials, as many media outlets have falsely characterized the certification as saying," they added.

The certification that Bobb signed, however, states that "any and all responsive documents accompany this certification." Trump did not, however, turn over all classified documents at Mar-a-Lago.

Bobb has since testified to the grand jury, and another attorney who worked on the draft response to the subpoena, Evan Corcoran, was recently forced to testify to the federal grand jury about the response and other discussions with Trump, after prosecutors believed Trump used his attorney to advance a crime.

Wednesday's letter also did not note that the FBI's August 2022 search warrant came after federal investigators were told that Trump directed the movement of boxes from a basement storage room to his residence at Mar-a-Lago following receipt of the subpoena.