Story highlights FBI Director James Comey is expected to testify before Congress Thursday

Top White House surrogates have left open the option of using executive privilege

(CNN) House Minority Leader Nancy Pelosi said Monday it would be "very incriminating" if the White House tried to block former FBI Director James Comey's from testifying before Congress later this week.

"There's a possibility of obstruction of justice, flirting with it, in any event, coming out of the White House," Pelosi, appearing on ABC's "The View," said about a reported discussion between President Donald Trump and Comey earlier this year about the Justice Department's investigation about Russian interference in the 2016 campaign.

Pelosi added, "I think if the President were to say he shouldn't testify, that would be very incriminating for the President."

Top White House surrogates have left open the option that Trump could invoke executive privilege to prevent Comey from testifying Thursday. White House Counselor Kellyanne Conway told NBC's "Today" on Monday that "the President will make that final decision."