Speaking at the Edinburgh Festival Fringe, the Speaker of the House of Commons further risked infuriating Boris Johnson with his comments on Wednesday.
The Prime Minister has refused to take no-deal off the table as part of his "do or die" commitment to leaving the EU by the October 31 deadline.
Mr Bercow was asked about attempts to suspend Parliament at his Fringe show by Channel 4 News.
"The prorogation that has been mooted from time to time - which I know the Prime Minister has indicated is not his intention - won't happen," he replied.
"It simply won't happen. I don't know what part of 'it won't happen' people either don't understand or refuse to believe.
"I am absolutely certain in my own mind that it will not happen."
He reportedly did not respond to questioning on how a suspension could be stopped, but did suggest the possibility of "massive public outcry" and "lengthy legal cases".
Mr Johnson has said his preferred option is to broker a new departure deal with Brussels.
But the EU has repeatedly refused to renegotiate it, including the Irish backstop which the Prime Minister wants scrapped.