This year's supply of Christmas trees to decorate the Vatican during Advent and Christmastide is not going smoothly.

One might think that of all the things about the Vatican which might generate controversy, its annual choice of Christmas trees, in particular the one that takes pride of place in St. Peter's Sqaure, ought to be fairly near the bottom of the list and, if anything, a source of goodwill instead.

But the Vatican's Christmas tree has in fact occasionally proved a lightning rod since 1982, when installing a tree for the festive season in St. Peter’s Square first became an annual tradition.