A report commissioned by the mayor's office and carried out by independent researchers at Cambridge Econometrics claims that should Britain leave the European Union without a deal in place, London stands to lose 6,000 creative industries jobs by 2030, with the country as a whole facing the loss of 27,000 creative jobs.
The scenarios assessed range from leaving the single market, the customs union, leaving both together and failing to get a transition deal, described by the study as "hard Brexit".
A worst-case no-deal Brexit scenario could mean 87,000 fewer jobs in London alone by 2030.
Khan said: "This independent analysis reveals the potential economic risks, and human costs, at stake in the negotiations".
Labour mayor Khan, who campaigned for Remain, told Sky News: "The analysis concludes that the harder the Brexit we end up with, the bigger the potential impact on jobs, growth and living standards".
BBC host Carrie Gracie questioned the motives that pushed Mr Khan to commission the reports, addressing his negative opinions on the negative effects Brexit could have on Britain. The report warns of a worsening skills shortage after Britain leaves the single market.
The report, which models five possible scenarios for leaving the European Union ranging from a near-status quo situation to leaving on World Trade Organisation terms without any transition agreement, warns that the worst option could be a "lost decade" of economic slump. Ministers are fast running out of time to turn the negotiations around.More news: Honda previews Insight prototype
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"And the reason why it's so important is because whatever deal the government negotiates has a direct impact on the quality of lives of families across the country".
"Their complete lack of preparation is irresponsible, leading to fears that they are putting party politics ahead of the national interest".
"The results show that Brexit will not only reduce the size of the United Kingdom economy, compared to what may have happened if the United Kingdom remained in the single market and customs union, but also put it on a slower long-term growth trajectory".
"The fact is, the economic collapse that Remainers like Sadiq Khan predicted would happen immediately after the referendum, has not occurred".
There could be 92,000 fewer jobs in science and technology, and 43,000 fewer jobs in construction.
There is no mention of Northern Ireland, or Ireland, in the study by Cambridge Econometrics.