In a witness statement made public at the Inquiry on Tuesday, the Mayor said he “could not understand” why ministers did not share information with him in the weeks preceding the first lockdown in March 2020.
Mr Khan did not attend a Cobra meeting until March 16, despite London having by far the highest rates of Covid transmission during the first wave of the virus. A national lockdown was not imposed until March 23.
“I was both deeply worried, and furious that London had not been involved in conversations until this point,” he said.
Downing Street aides argued that Mr Khan could not attend the meetings as it would mean that invitations would have to be extended to other regional leaders, such as West Midlands mayor Andy Street or Manchester Mayor Andy Burnham.
When Mr Khan did eventually attend a Cobra meeting, he was told that London was “a few weeks ahead” and that the “rate of infection in the capital was far greater and spreading far quicker than anywhere else in the country”.
He wrote: “It was shocking to learn in that Cobra meeting for the first time just how bad things were. I remember that the PM referred to the need for draconian measures and said the country would not have faced anything like it since the Second World War.
“I simply could not understand why, particularly given the increasing severity of the outbreak in London and my repeated requests to attend previous Cobra meetings in order to be informed, this information was only being shared with me at this stage.”
Mr Khan added: “I was both deeply worried, and furious that London had not been involved in conversations until this point.”
Earlier on Wednesday, the Inquiry heard how the country’s most senior civil servant wanted Matt Hancock to be sacked as Health Secretary.
Former cabinet secretary Lord Sedwill said that he did not formally advise Boris Johnson to sack Mr Hancock but the prime minister would have been “under no illusions” about his feelings.
The inquiry heard that in one WhatsApp exchange with the permanent secretary at No 10 Simon Case – who is the current Cabinet Secretary – Lord Sedwill joked it was necessary to remove Mr Hancock to “save lives and protect the NHS”.
He told Lady Hallett’s inquiry that the remark, a play on the pandemic-era slogan, was an example of “gallows humour”.
“I had raised my concerns with the prime minister. That was not intended for him to remove Mr Hancock but to take a grip on the issue.”