Effective mitigation of the coronavirus health crisis partly depends on trust that the measures which are being imposed are worthwhile, and that the people who have decided them are trustworthy. Such basic trust has come under pressure over time, partly as society has become more questioning, and more recently through the spread of conspiracism online. There is some evidence of online actors exploiting the current emergency to generate distrust and undermine vaccine confidence. Widespread sense of insecurity - whether health-related, or due to economic hardship - may also sharpen distrust of authority. Undermining of public trust may inhibit return to stronger lockdown measures, the management of exit from lockdown, rollout of testing and contact tracing, and introduction of vaccination programmes. Governments and public health bodies accordingly need high-quality evidence on the sources of distrust and noncompliance, and on the health and public security threats posed by the dissemination of conspiracism. We will analyse whether endorsement of conspiratorial accounts of the pandemic undermines trust and compliance, or whether the relationship works the other way around. This will be delivered through robust analysis of new, high-quality survey data tracking both those who endorse conspiratorial views and those who do not over the coming months. Subject to their agreement, we will also sample respondents' posts from a popular microblogging service, to track their online information sharing against their reported attitudes, identities and behaviours.