(CBSNews) -- Deputy Attorney General Rod Rosenstein is expected to resign from his post at the Justice Department in a few weeks, CBS News confirms. Rosenstein is planning to depart when the new attorney general, William Barr, is expected to be confirmed. CBS News correspondent Paula Reid was told Rosenstein always saw this as a two-year position and wants to ensure a smooth transition. But the timing is surprising.

It's unclear what Rosenstein's departure means for the special counsel investigation, which he has overseen since he appointed Robert Mueller. Barr will likely inherit oversight of the investigation, but that is not a guarantee. His previous criticism of the investigation is expected to be a central theme in his confirmation hearings next week.

On Tuesday, attorneys for Paul Manafort, former Trump campaign chairman, submitted a poorly redacted filing on Tuesday revealing Manafort shared polling data with a Russian operative during the campaign. President Trump has consistently denied any coordination between his campaign and Russia. This is the clearest evidence yet of contacts between his campaign and Russian businessman with ties to Russian intelligence during the campaign. This is the kind new information we expect in Mueller's final report.

But congressional Democrats have vowed to make sure the whole report is made public. The president's legal team has signaled they may try to block portions that deal directly with the president.