We show in three dimensions, using functional integral techniques, the equivalence between the partition functions of the massive Thirring model and a gauge theory with two gauge fields, to all orders in the inverse fermion mass. Detailed bosonisation identities, also valid to all orders in the inverse mass, are derived. Specialisation to the lowest (and next to lowest) orders reveals that the gauge theory simplifies to the Maxwell-Chern-Simons theory. Some interesting consequences are discussed in this case.