Due to issues surrounding data quality and coverage, there is currently limited systematic evidence available on the nature and significance of deep poverty in the UK. Through a mixed-methods longitudinal design, this research examines the changing income dynamics, socio-demographic composition and concentrations of poverty, to establish what can be done to better support those on the lowest incomes. The focus and direction of the research is informed by a project steering group made up of experts by experience, practitioners, campaigners and academics.