Recent transport equity literature has proposed a sufficientarian approach to transport planning, according to which all individuals would be entitled to a minimum level of accessibility deemed adequate or sufficient. The implementation of this approach would require the adoption of an accessibility standard as a key performance indicator guiding transport investments, land use planning and service provision. While accessibility measures are increasingly operationalised in professional practice, the adoption of actual accessibility standards is rare. In this paper, we explore the barriers for adopting explicit accessibility standards and identify conditions within which such standards could be acceptable to practitioners and policymakers. The paper draws on interviews with professionals in three city-regions in Sweden, complemented with interviews with practitioners from the Flanders region in Belgium and from the UK. We find that authorities are hesitant to define and measure accessibility and that where definitions and performance indicators exist, there is a lack of agreement within and across authorities. The prospect of introducing a standard across the board without attaching any conditions comprises a further reason for shying away from standard-setting. The (dis)integration of transport and land use and complicated administrative and governance structures are described as a further barrier, while demand responsive transport is in some cases considered a panacea to all accessibility problems, making it possible to avoid setting standards. Our findings suggest that standards for minimum accessibility could gain political support if their reach is clearly circumscribed, and their benefits are clearly understood.