The Prime Minister was grilled at the Commons Liaison Committee Wednesday afternoon on the departure of his former Health Secretary for breaching covid rules.
Mr Hancock, who is married, resigned the day after photos and videos of him kissing his part-time adviser, Gina Coladangelo, in his office were published.
Downing Street initially stood by the former minister, only for Mr Johnson to insist he was right to go.
Labour MP Chris Bryant repeatedly asked Mr Johnson at the Commons Liaison Committee whether or not he had sacked him.
“On your question about Mr Hancock, the former health secretary, let me just go back to what I said many, many times, and I think I said on the floor of the House of Commons,” the Prime Minister told MPs.
“Which was that we all read about the story concerning Mr Hancock and the CCTV and so forth on I think the Friday, and we had a new health secretary on the Saturday.
“And considering that we are in the middle of a global pandemic, and it’s quite a thing to move your health secretary, Mr Bryant, I think that was quite fast-going if I may say so and that’s all I have to say on that matter.”
It came in a session that also saw Mr Johnson insist “higher skilled jobs” are the “best way forward” when asked to reconsider plans to end the Universal Credit uplift.
Just days ago six former Conservative work and pension secretaries urged the Chancellor to make the uplift permanent, warning that failing to do so would “damage living standards, health and opportunities” .
Asked if he accepted that removing the uplift could cause hardship to many people, the Prime Minister told the Liaison Committee: “I think that the best way forward is to get people into higher wage, higher skilled jobs.
“That’s the ambition of this Government and if you ask me to make a choice between more welfare or better, higher paid jobs, I’m going to go for better, higher paid jobs.”
When asked if the Government would review the policy between now and September, Mr Johnson said: “Of course we keep everything under constant review but I’ve given you a pretty clear steer about what my instincts are.”
Mr Johnson also told MPs “it looks as though” Step 4 of England’s road map out of lockdown will go ahead as planned on July 19.
He said: “Thanks to the vaccine rollout we were able to get through to Step 3.
“Now it looks as though – we will take the final decision on July 12 – but it looks as though we will get through to Step 4, which will allow them (hospitality venues) to open up fully without the need for the one-metre rule.
“All these decisions are a balance of risk. This is a highly contagious disease. We have to do what we can to stop its spread.
“We have been looking at all the data and trying to strike the right balance. "