Canonical approach to Lagrange multipliers
  Lagrange multipliers are present in any gauge theory. They possess peculiar gauge transformation which is not generated by the constraints in the model as it is the case with the other variables. For rank one gauge theories we show how to alter the constraints so that they become generators of the local symmetry algebra in the space of Lagrange multipliers too. We also discuss the limitations on using different gauge conditions and construct the BRST charge corresponding to the newly found constraints. 
M.N. Stoilov