Mr Powell, who lives in South Cambridgeshire, still keeps in touch with his former constituency and makes a 'modest' donation to the Corby association.
In an interview with this paper Mr Powell, MP for Corby for 14 years from 1983 to 1997, said that 'enough is enough' and Mr Johnson should go and that he had 'fooled around' with Tory voters.
Mr Powell, 73, said: "I would like to start by saying I am, and always have been, a very strong supporter of the party.
"The Prime Minister is a disgrace. He has fooled around with Conservative supporters for too long. The sooner he faces up to it and leaves the better. He shouldn't wait for reports and he should go.
"He knows that public knows he has made a fool over himself over Owen Paterson and the public spending plans. Enough is enough."
A former barrister, Mr Powell, now retired and living in a village near Cambridge, is still a Conservative Party member in South Cambridgeshire, and still takes an interest in Northamptonshire politics.
Speaking of Mr Johnson's apology for the 'partygate' gatherings in the garden at number 10 Mr Powell said an apology was not sufficient.
He said: "The only apology he can make is to go. He is the leader and he's hiding and it's making governing impossible."
Mr Powell praised the current MP for Corby Tom Pursglove for his 'excellent' work.
He said: "Tom Pursglove has done an excellent job but he is a government minister and he can't say anything without resigning."
Mr Powell added: "I'm certain that the people of Corby agree that he [Mr Johnson] has to go."