Can we the Srivaishnavas accept the prasadam prepared by a non Srivaishnava Brahmin in a temple?

Only Srivaishnavas should prepare food in a temple; it is better if that person transforms into a Srivaishanava.
This is a tricky situation; it is better if it is accepted as Perumal prasadam but one has to ponder carefully if the food is not cooked by a Srivaishnava.