(CNN) In a significant shift, the Justice Department will extend an offer on Thursday to top lawmakers on Capitol Hill to review certain documents related to the FBI's use of a confidential intelligence source during the 2016 presidential campaign early next week, according to a senior Justice Department official.

The move represented a notable concession for the department in an ongoing saga over the FBI source who reportedly met with at least three Trump campaign aides during the campaign -- a point President Donald Trump has seized on in recent weeks to assert, without evidence, that his campaign was wrongfully spied on.

House Intelligence Chairman Devin Nunes served the department with a subpoena for the documents, threatening to hold Deputy Attorney General Rod Rosenstein in contempt of Congress on several occasions if he did not turn them over.

Initially, the Justice Department resisted providing Congress with the materials, fearing the source's life would be placed at risk, but it later decided to provide members with classified briefings to answer questions.

On May 24, top officials at the Justice Department, the FBI and the Office of the Director of National Intelligence provided two briefings to lawmakers, but the scope of what exactly was revealed about the source's work was unclear at the time.

Read More