Boris Johnson admitted his top team was too “male-dominated” as he defended his Downing Street operation from claims it had a “toxic” atmosphere.

The former prime minister was presented with claims – including from former top civil servant Helen MacNamara – that Number 10 was a dysfunctional working environment and former adviser Dominic Cummings contributed to a “toxic” working culture.

Facing his first day of evidence in Baroness Heather Hallett’s Covid inquiry, Mr Johnson sought to play down some of the inflammatory language contained in released WhatsApp messages while insisting that any administration under similar pressures would have behaved in the same way.

He told inquiry lead counsel Hugo Keith KC he would make a “distinction between the type of language used and the decision-making processes of the Government and what we got done”.

He said: “And I would submit that any powerful and effective government, and I think of the Thatcher government or the Blair government, has a lot of challenging and competing characters whose views about each other might not be fit to print but who get an awful lot done – and that’s what we did.

“I think that actually what you’re looking at, in all this stuff, is a lot of highly talented, highly motivated people who are stricken with anxiety about what is happening about the pandemic, who are doing their best and who, like all human beings under great stress and great anxiety about themselves and their own performance, will be inclined to be critical of others.”

Mr Johnson said that would be the “same” under any other administration.

“It would not have been right, if we’d had a load of WhatsApps saying, ‘Aren’t we doing brilliantly, folks? Isn’t this going well?’. I think your criticisms might have been, frankly, even more pungent.”

Mr Johnson said he wanted “an atmosphere of challenge with some strong characters giving me advice, and I valued that advice”.

The inquiry has been told by witnesses that Mr Johnson’s No 10 operation was chaotic and dysfunctional.

In July 2020, Simon Case, then the head official in Downing Street and now the Cabinet Secretary, said “I’ve never seen a bunch of people less well-equipped to run a country” in a message to Sir Mark Sedwill, who was cabinet secretary at the time.

But Mr Johnson said: “I think that the worst vice, in my view, would have been to have had an operation where everybody was so deferential and so reluctant to make waves that they never expressed their opinion, they never challenged and they never doubted.

“It was much more important to have a group of people who are willing to doubt themselves and to doubt each other. And I think that that was creatively useful rather than the reverse.”

Asked about claims he called then-health secretary Matt Hancock “totally f***ing hopeless” during the pandemic, Mr Johnson said: “The country as a whole had notable achievements during the crisis. My job was to try to get a load of quite disparate, quite challenging characters to keep going and through a long period and to keep doing their level best to protect the country. That was my job.”

He also defended keeping Mr Hancock in his post despite pressure from Mr Cummings to sack him.

Mr Johnson said: “If you’re prime minister, you are constantly being lobbied by somebody to sack somebody else. It’s just what, I’m afraid, happens and it’s part of life.”

He acknowledged Mr Cummings had a “low opinion” of Mr Hancock but “I thought he was wrong”.

He said: “I stuck by the health secretary. I thought the health secretary worked very hard.”

He said Mr Hancock “may have had defects” but “I thought that he was doing his best in very difficult circumstances and I thought he was a good communicator”.

Pressed on another claim that civil servants did not want to join the Number 10 team because of the wider culture, Mr Johnson denied any knowledge of it and said Downing Street had not had a problem recruiting officials.

“I was not aware of that. Secondly, I didn’t see any sign of that. I saw brilliantly talented people,” he said.

But he conceded his top team was too “male-dominated”.

“I think that the gender balance of my team should have been better,” he told the inquiry.

“I think sometimes during the pandemic too many meetings were too male-dominated, if I’m absolutely honest with you.”

Mr Johnson suggested the tone of the WhatsApp exchanges disclosed to the inquiry reflected the “agony” being felt in the country and the “very frazzled” people struggling to respond to the pandemic.

“It was a very difficult, very challenging period. People were getting – as you can see from the WhatsApps – they were getting very frazzled because they were frustrated,” he said.

“Covid kept coming at us in wave after wave and it was very, very hard to fight it.

“People were doing their level best. When people are critical of the guy at the top or they are critical of each other, that’s a reflection of the difficulty of the circumstances.”