Urban food cultivation in the United Kingdom: Quantifying loss of allotment land and identifying potential for restoration

•Allotment land area in Britain has declined by two-thirds since its peak.•A quarter of former sites have the potential for reconversion to use as allotments.•The most deprived urban areas have experienced eight times the level of allotment land loss than the least deprived areas.•The history of site closures provides insights to help meet present day demand.