In his celebrated 1987 essay, ‘The monarchical republic of Queen Elizabeth I’, Patrick Collinson wrote that ‘Elizabethan England was a republic which also happened to be a monarchy: or vice versa.’ Since then, the idea of an Elizabethan ‘monarchical republic’ has been tested, challenged, and developed, with precedents found in Henry VIII's and Edward VI's reigns. Mary I's reign has not, however, been considered for its contribution to the debates. Yet, in 1553, the unique circumstances of Mary's accession as England's first queen regnant, who was also still legally a bastard, exacerbated sixteenth-century anxieties about monarchical authority, and about the correct relationship between a monarch and parliament. Prior to Mary's coronation, her council put forward an unprecedented proposal: they wanted parliament to sit before Mary was anointed and crowned queen. This article explores this proposal, in conjunction with two texts, Richard Taverner's An oration gratulatory made upon the joyfull proclayming of the moste noble Princes Quene Mary Quene of Englande and the play Respublica, to argue that, at the beginning of her reign, significant pressure was put on Mary to rule her country as a ‘monarchical republic’.