Boris Johnson says that the UK will leave the EU on the 31 October 2019, “do or die.” Assuming he succeeds in this goal, the UK seems set to leave without a withdrawal agreement—a “no deal” scenario. Health is central to Brexit. The Leave campaign claimed that Brexit would provide £350m ($390m; $430m) a week for the NHS and Johnson, on becoming prime minister, announced what he misleadingly described as “new” spending on the NHS. Thus, many people may think that a no deal Brexit will do no harm and could even be good for health and the NHS. But will it? Two previous analyses have set out, in detail, why any form of Brexit will be damaging,1 2 and a leaked government document, written in early August 2019, paints an even more alarming picture.3 This contrasts starkly with the prime minister’s reassurances that the UK will “cope easily.”