Sadiq Khan said "lives could have been saved" if he had been invited to key Government meetings earlier on in the pandemic.
Giving evidence to the Covid-19 Inquiry, Mr Khan confirmed that repeated requests to attend the meetings in March 2020 were rejected by No 10 on the grounds that other mayors would also have to be present.
He said: “I was told that something in London was different because I was told the pandemic was having an impact on London ahead of the rest of the country.
“The Government was aware of the challenges in ICU, the challenges in our hospitals, and the Government was aware of community transmission in London.”
Ahead of the appearance, written evidence from the Mayor recalled his shock at being told how Covid was ripping through London in the early stages of the pandemic.
In a statement to the inquiry, the mayor said it was “shocking” to learn directly from the Government for the first time “just how bad things were” when he was invited to his first COBR meeting on March 16, 2020.