Former U.S. Attorney Preet Bharara on Sunday said there is “absolutely evidence to begin a case” against President Donald Trump for obstruction of justice.

“I think there’s absolutely evidence to begin a case,” Bharara said on ABC News’ “This Week.”

In March, Trump asked Bharara, formerly U.S. attorney for the Southern District of New York, to resign from his position just months after personally asking Bharara to stay on.

“I think it’s very important for all sorts of armchair speculators in the law to be clear that no one knows right now whether there’s a provable case of obstruction,” Bharara noted on Sunday, but added: “It’s also true, I think, from based on what I see as a third party and out of government, that there’s no basis to say there’s no obstruction.”