Boris Johnson had the wrong “skill set” to lead the country through the pandemic, leaving his senior aides “exhausted” by constantly changing his mind on crucial decisions, the UK Covid inquiry has heard. Lee Cain, the former Downing Street director of communications, told the inquiry the severity of the crisis required firm and constant leadership, which the former prime minister was unable to provide. The former senior aide described Johnson’s words at a press conference in spring 2020 as “unhelpful” when the prime minister indicated that the UK could get the Covid virus under control within 12 weeks as it “set a very unrealistic expectation of where the nation needed to be at that point”. Asked by the inquiry’s lawyer whether he agreed with WhatsApp messages from Dominic Cummings, the former top No 10 aide, that suggested that Johnson might not be up to the job, Cain said: “I think that’s quite a strong thing to say. “I think what will probably be clear in Covid, it was the wrong crisis for this prime minister’s skillset. Which is different, I think, from not potentially being up for the job of prime minister.” He added: “He’s somebody who would often delay making decisions. He would often seek counsel from multiple sources and change his mind on issues. Sometimes in politics that can be a great strength … “If you look at something like Covid, you need quick decisions and you need people to hold the course and have the strength of mind to do that over a sustained period of time and not constantly unpick things … I felt it was the wrong challenge for him mostly.” Cain said that while it was “understandable” that Johnson had “oscillated” between locking down the country and other policy options, those moment of indecision seriously impacted on the pace of the government’s reaction – and that his approach was “more difficult to defend” later in the pandemic. However, Cain defended the 10-day gap between agreeing that the country should lock down on 14 March 2020 and it happening, despite being challenged by the inquiry chair Baroness Hallett, who told him she found his comments “curious”. “It’s longer than you would like but important to emphasise the amount of things that had to be done and the amount of people we had to take with us to deliver a nationwide lockdown. From my understanding, that’s government moving at tremendous speed,” he said. In WhatsApp exchanges seen by the inquiry, sent in March 2020, Cummings complained that Johnson was in “Jaws mode”, predicting that it was “only a matter of time” before his “babbling” exposed the fact he did not know what to say to the media, while Cain had said that he was “exhausted” by the former prime minister. “Anyone that’s worked with the prime minister for a period of time will become exhausted with him,” Cain told the inquiry. “Sometimes he quite challenging character to work with, just because he will oscillate, he will take a decision from the last person in the room.”