The study said that in a no-deal scenario, the industry that fares the worst will be financial and professional services, with as many as 119,000 fewer jobs nationwide.
A study commissioned by London Mayor Sadiq Khan shows that nearly half a million jobs are under threat if Britain fails to strike a deal on future relations with the European Union before it leaves the bloc.
"This new analysis shows why the Government should now change its approach and negotiate a deal that enables us to remain in both the Single Market and the Customs Union", he crowed, proposing a so-called "Soft Brexit".
The report compares four possible post-Brexit scenarios to the option of maintaining the status quo - already ruled out by the British government - of staying in the European single market and customs union.
London Mayor Sadiq Khan, who campaigned against Brexit, commissioned the study and said the findings show "the potential economic risks - and human costs - at stake in the negotiations" in Brussels.
The assessment, carried out by Cambridge Econometrics, says economic output across the United Kingdom could be on average between 3% lower by 2030 than it would if Britain were to remain within the single market and customs union.
NHS crisis in Cumbria: Wards full, beds blocked and ambulance handovers delayed
At UHNMT, 99.3 per cent of 1,421 beds were full on December 28, with the average for the period hitting nearly 98 per cent. Jeremy Hunt yesterday acknowledged the health service needed "substantially more resources" in the future.
The London mayor has this morning published an analysis of a worst-case Brexit scenario, and what it would mean for the capital.
It looks at the impact on various regions and industries and follows Brexit Secretary David Davis admitting that the Government had not conducted any impact assessments.
He added: "The analysis concludes that the harder the Brexit we end up with, the bigger the potential impact on jobs, growth and living standards". Ministers are fast running out of time to turn the negotiations around.
Both the London mayor and Cambridge Econometrics admit that this analysis is not a precise forecast of what will happen. "It is clear that a no-deal, hard Brexit without a transitional deal will place all this under threat".
A spokesperson for the Department for Exiting the European Union said: "The fact is we are working to secure the best and most ambitious Brexit deal for the whole of the United Kingdom".
"The UK wants a deep and special partnership with the European Union, a partnership that spans a new economic relationship and a new relationship on security".