Former CIA Director John Brennan warned his employees in an internal memo last December that some members of Congress did not “understand and appreciate the importance of gravity” of Russia’s interference in the 2016 presidential election, Buzzfeed News reported Thursday.

The memo, which Buzzfeed obtained through a Freedom of Information Act request, did not mention the specific lawmakers who Brennan referred to by name. Three unnamed intelligence sources told the publication that the lawmakers in question were Senate Majority Leader Mitch McConnell (R-KY) and John Cornyn (R-TX), a particularly close ally of the Trump administration.

In the months since President Donald Trump took office, both McConnell and Cornyn have continued to downplay Russia’s interference in the U.S. election and any possible assistance the Trump team may have provided for that effort.

Brennan testified in May on the collective assessment that he and other intelligence leaders reached about Russia’s “brazen” interference in the 2016 race through bots pushing fake news and the release of emails hacked from Democratic Party organizations and operatives.

Under oath before the House Intelligence Committee, Brennan said that the Trump campaign’s contacts with Russia warranted investigation. He also said that he left office with “unresolved questions” about whether Russian officials successfully convinced members of the campaign “to act on their behalf—wittingly or unwittingly.”

Four congressional committees and a special counsel are currently investigating Russia’s election interference and relationship with the Trump campaign.