Les Barker's parody is called Blessed Are The Peacemakers and is on The Mrs Ackroyd Band's Gnus and Roses CD (DOG010). The composing credit is Barker/Tchaikovsky, and the vocals are by Les Barker, Lesley Davies, Alison Younger, Norma Waterson, Eliza Carthy and June Tabor. I have the words on the CD sleeeve, but won't be able to transcribe them until next week.