Boris Johnson vowed not change his behaviour following a double drubbing in crucial by-elections in a bizarre series of broadcast interviews.
The Prime Minister said the idea that he would undergo a “psychological transformation” following the embarrassing defeats was “not going to happen.”
And he indicated he thinks serious questions about his ethical conduct “doesn’t matter.”
“As a leader you have to distinguish between the criticism that really matters and the criticism that doesn’t,” he told the BBC during a trip to Rwanda for the Commonwealth Heads of Government Meeting (CHOGM).
He claimed the public were “heartily sick of hearing about me and the things I'm alleged to have done wrong.”
And he told Sky News his party suffered the crushing defeats because “people were absolutely fed up hearing about things I stuffed up, this endless churn of stuff, when they wanted to hear what is this guy doing."
He said the lesson he took from losing two seats in one night was “that we've just got to get the focus on all the things we're doing to take the country forward."
Asked if he was going to change his behaviour as a result of the by-election results, and following Oliver Dowden's letter, the PM said: "If you're saying you want me to undergo some sort of psychological transformation, I think our listeners will know that is not going to happen."
And he claimed the "only actual argument I've heard some of my critics make of substance about the change of direction they'd like to see is about going back into the EU single market. That's literally the only manifesto point I've seen."
Asked if there were any circumstances under which he would consider resigning on principle, he said: "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.
Presented with a string of transgressions for which people have called for his resignation, including lawbreaking and misleading the house, Mr Johnson said: "Hang on, let's look at this in a more cheery way, if that is possible.
"Actually what's happened is that I've got a renewed mandate from my colleagues, and I'm going to deliver."
