Objectives: To study the prevalence of COVID-19 health protective behaviours before and after rules eased in England on the 19th July 2021.Design: Observational study pre (12th-18th July) and post (26th July-1st August) 19th July, and a cross-sectional online survey (26th to 27th July).Setting: Observations occurred in supermarkets (n = 10), train stations (n = 10), bus stops (n = 10), a coach station (n = 1) and a London Underground station (n = 1). The survey recruited a nationally representative sample.Participants: All adults entering the observed locations during a one-hour period (n = 3819 pre- and n = 2948 post-19th July). In the online survey, 1472 respondents reported having been shopping for groceries/visited a pharmacy and 566 reported having used public transport or having been in a taxi/minicab in the last week.Main outcome measures: We observed whether people wore a face covering, maintained distance from others and cleaned their hands. We investigated self-reports of wearing a face covering while in shops or using public transport.Results: In most locations observed, the proportion of people wearing face coverings, cleaning the hands and maintaining physical distance declined post 19th July. Pre 19th July, 70.2% (95% CI 68.7 to 71.7%) of people were observed to be wearing a face covering versus 55.8% (54.2 to 57.9%) post 19th July. Equivalent rates for physical distancing were 40.9% (39.0 to 42.8%) versus 29.5% (27.4 to 31.7%), and for hand hygiene were 4.4% (3.8 to 5.1%) versus 3.9% (3.2 to 4.6%). Self-reports of “always” wearing face coverings were broadly similar to observed rates.Conclusions: Adherence to protective behaviours was sub-optimal and declined during the relaxation of restrictions, despite appeals to exercise caution. Self-reports of “always” wearing a face covering in specific locations appear valid.