Pope Benedict warned yesterday against rampant materialism which he said was polluting the spirit of Christmas. ?In today?s consumer society, this time of the year unfortunately suffers from a sort of commercial ?pollution? that threatens to alter its real spirit,? the Pope told a large crowd gathered in St. Peter?s Square to hear his weekly Angelus blessing.

He said Christmas should be marked with sober celebrations and urged Christians to display a nativity crib in their houses as ?a simple but effective way of showing their faith and conveying it to their children?.

Last year, under Pope John Paul, the Vatican launched a high-profile campaign to urge Roman Catholic Italy not to compromise the spirit of Christmas through excess or dilute its message out of fear of offending a growing Muslim population.