BEIJING — The dramatic religious revival in China has been acknowledged by Beijing for the first time with a survey suggesting the number of adherents is three times the official figure.

Beijing also accepts by implication that there are tens of millions of Christians who do not worship in state-registered churches, a significant acknowledgment as negotiations with the Vatican over a resumption of diplomatic relations appear to have stalled.

International groups have also been active in trying to draw attention to the persecution of the growing number of underground Christian churches in the country.

The survey, published in the China Daily newspaper, the international mouthpiece of the Communist Party, said 31% of the adult population — defined as over 16 — described themselves as religious, which works out to be about 300 million people.

Official figures say there are 100 million religious adherents, a number which the paper noted without comment “has remained largely unchanged for years.” It described the new number as “startling.”

Beijing has changed tack on religion dramatically in recent years, despite remaining officially atheist and demanding that party members do not belong to a religion, an instruction widely ignored.