UK policy was to allow 1,000 new cases per day
As documented in the Joint Biosecurity Centre Note on Joint Biosecurity Centre and potential flows, 20 May 2020 It has obviously been policy to tolerate a level of New Cases. Now we know that level was 15 new cases per day, per million people, if a UK figure, or 18 cases a day if it was a figure for England We also can see from the graphs that policies were altered to allow the case rate to start rising again - when the UK new case rate hit 15 per day