He said he must “humbly and sincerely” accept any criticism he receives in his job, but argued every Government gets “buffeted” by bad by-election results mid-term.
He said his role is to look at exactly what happened and “think which criticisms really matter”.
Put to him that Oliver Dowden had resigned as Conservative chair saying business could not continue as usual, Mr Johnson told BBC Radio 4’s Today programme: “If you’re saying you want me to undergo some sort of psychological transformation, I think that our listeners would know that is not going to happen.
“What you can do, and what the Government should do, and what I want to do, is to get on with changing and reforming and improving our systems and our economy.”
The Conservative leader also suggested he would stand down as Prime Minister if it was put to him he had to “abandon the Ukrainian cause”.
Asked over which matters of principle he might resign, he told BBC Radio 4’s Today: “Well, for instance, I think that if our Government decided, if it was put to me that we had to abandon the Ukrainian cause because it was simply getting too difficult, and that the cost of supporting that people in their heroic fight for freedom was too great in terms of inflation, in terms of economic damage, yeah, I think I would accept that I’d lost a very important argument and I would go, but I don’t see that.”
But he later denied saying this was the only principle that would trigger such a move.
“I didn’t say that – you asked me for an example of a matter of principle, I came up with one,” he said.
Asked about his comments on Friday that he expects voters to beat him up, Boris Johnson told Sky News: “Well, I was speaking metaphorically and what I mean is that when you’re the leader of a country, in good times and in bad, you have to think about the criticisms that you get.
“And you have to recognise that inevitably when you’re the head of a government that’s taking the country through a big inflationary price caused by the increasing cost of energy, people are frustrated. People are filling up their cars, and cursing as they do so.
“I understand that, we have to help them – and I understand people’s frustration.
“So what I’m saying is politics is about allowing people to have the democratic safety valve of letting off at governments, such as in by-elections. But then the job of a leader is to say, well, what is the criticism that really matters here?
“And I think back to what I was saying, I think it’s, for a long time people were hearing not enough about the things that really matter.”