Monsignor Javier Herrera-Corona, the Vatican's unofficial representative in Hong Kong, delivered a stark message to the city's 50-odd Catholic missions before finishing his six-year posting in March: the freedoms they had enjoyed for decades were over.

In four meetings held over several months, starting in October last year, the 54-year-old Mexican prelate told Catholic missionaries in Hong Kong to prepare for a tougher future as China tightens its control over the city, and he urged his colleagues to protect their missions’ property, files and funds, according to four people familiar with the private sessions, who asked not to be identified because of the sensitive nature of the discussions.

"Change is coming, and you'd better be prepared," Herrera-Corona warned the missionaries, according to one of the people, who said he was summarizing the monsignor’s message: "Hong Kong is not the great Catholic beachhead it was."