James Comey, the former director of the FBI, has said that the Mueller report contains sufficient evidence that Donald Trump committed obstruction of justice that he would have been charged, were he not president.

Comey is the latest in a growing list of former federal prosecutors and senior judicial figures who have said that the factual details contained in Robert Mueller’s report into Russian meddling in the 2016 presidential race would be grounds for indicting Trump with multiple felony charges for obstruction. A joint letter to that effect has now been signed by 803 individuals.

Asked in a CNN town hall on Thursday night whether he agreed with that conclusion, Comey said he did. “There are a whole lot of facts in Bob Mueller’s report that raise serious questions about whether there’s a chargeable case for obstruction and witness tampering against this president,” he said.

Comey’s pointed words carry particular weight as it was his firing as FBI chief in May 2017 that prompted the appointment of Mueller as special counsel. The CNN event was held on the second anniversary of that firing.

Comey said the key to any obstruction charge was criminal intent on the part of the perpetrator, and in at least two incidents recorded in the Mueller report, Trump had displayed that purpose. The first was when Trump directed the former White House counsel Donald McGahn to fire Mueller himself.

“The direction to Don McGahn to get the special counsel fired is to my mind a flaming example of corrupt intent,” Comey said.

The second episode Comey cited involved Trump trying to limit the scope of the special counsel’s investigation. The Mueller report revealed that Trump asked his former campaign manager Corey Lewandowski in June 2017 to tell the then US attorney general, Jeff Sessions, to restrict the investigation to future elections only – ruling out the inquiry into Trump’s behavior in 2016.

Comey said that the Sessions and the McGahn episodes were “examples that any reasonable prosecutor would charge”.

Under justice department guidelines, a sitting president cannot be charged with a criminal offense for deeds committed in office. Broadly speaking, the decision to charge the president is left to Congress through the impeachment process.

However, Comey noted that Mueller had made a point of laying out the facts for the potential benefit of future prosecutors once Trump’s term has ended.

Asked whether Trump should be charged after his presidency ends, Comey replied: “I think the justice department will have to take a serious look at that. Whether that’s a wise thing to do, I don’t know.”

Trump on Thursday tried to smear both Comey and Mueller, saying at an impromptu press conference that the special counsel “is in love with James Comey. He liked James Comey. They were very good friends. Supposedly best friends. Maybe not, but supposedly best friends.”

“I don’t think we have that kind of relationship,” Comey quipped on CNN. “I can’t wait to see all the pictures of us hugging and kissing because they are not on my iCloud account.”