Labour accused Mr Johnson of “trying to rewrite history” by indicating on Monday he acted over concerns that Mr Hancock undermined the coronavirus messaging by breaching Covid-19 guidance when he kissed an aide.
This ran contrary to No.10’s insistence on Friday that Mr Johnson “considers the matter closed” in standing by the then-minister and his ultimate resignation the following day.
Downing Street said the pair held talks on Saturday and, having “discussed it further”, Mr Johnson backtracked to agree that Mr Hancock had to stand down.
During a by-election campaign visit to Batley on Monday, Mr Johnson suggested he acted over Mr Hancock because it undermined the UK Government’s message the nation has been in the pandemic together.
“That’s right,” Mr Johnson told broadcasters. “And that’s why when I saw the story on Friday we had a new Secretary of State for Health in on Saturday.”
Labour deputy leader Angela Rayner accused Mr Johnson of trying to take credit for the resignation and said that “serious unanswered questions” remained.
“Boris Johnson is trying to rewrite history because he didn’t have the guts to sack Matt Hancock,” Ms Rayner said.
“A fish rots from the head down, and by failing to sack the former health secretary, Johnson proved he doesn’t have the leadership qualities or judgment required to be Prime Minister.”
The Prime Minister’s official spokesman came under sustained questioning over the handling of the Hancock scandal.
Asked if Mr Johnson sacked him, the spokesman said: “No, the former health secretary resigned.”
And asked if Mr Johnson urged Mr Hancock to resign, the spokesman said: “No, the Prime Minister accepted his resignation, he agreed it was the right decision.”
Downing Street also insisted Mr Hancock and health minister Lord Bethell did not use personal email addresses for government business.
Asked about Matt Hancock’s use of a private email address instead of his government account, the Prime Minister’s official spokesman said: “My understanding is it’s related to things like diary acceptances.
“The rules for the use of private email are set out clearly.”