The Roman Catholic Church in England and Wales says it faces an acute shortage of men becoming priests.
Sunday is reserved for prayer for the priesthood
Professor Noel Tims, a Roman Catholic academic has warned the number of priests in Britain is likely to fall by half within about a decade.
This comes on the day set aside by the Pope for prayer for more men to commit themselves to ordination.
There are currently 38 prospective priests for England and Wales entering seminaries this year.
Three years ago Mr Tims warned about the dwindling number or ordinations and the rapid increase in the age of priests.
He said then that the decline could lead to a halving of the number of priests within 10-15 years.
Three years on and the situation has not improved with a third of parishes in danger of finding themselves without a priest, according to religious affairs correspondent Robert Pigott.
Compulsory celibacy and the lower prestige of the priesthood are among the reasons blamed for the decline.
The same problem is evident elsewhere in western Europe and in North America.
Pressure is mounting for lay people to take on some of the duties of priests.
But only last week Pope John Paul II warned that only priests could fulfil certain duties within the Catholic faith.