The former bishop of Hong Kong, Cardinal Joseph Zen, has said the Vatican should not compromise with China over religious freedoms.

He told the Vatican-linked news agency AsiaNews that the Vatican should not place so much importance on forming diplomatic ties with Beijing.

Cardinal Zen said diplomatic ties could give the false impression that there was religious freedom in China.

China only allows Catholics to belong to a state-sanctioned church.

China cut ties with the Vatican in 1951, shortly after the Communist Party took power.

"We've come to the point where it's not possible just to accept compromise as we did before," he said of Pope Benedict XVI's attempts to improve the Vatican's often-tense relations with Beijing.

"In these two years there hasn't been a turn toward clarity. In fact, it seems to me that we're taking a worrisome slide along a slope of compromise."

Two years ago the Pope issued a letter to Chinese Catholics urging worshippers in banned "underground" churches to reconcile with followers of the Beijing-approved church.

The cardinal repeated a call for bishops in the official church not to give in to pressure from the government, saying they had to remain firm in their faith and loyalty to the Pope.

Cardinal Zen stepped down as Bishop of Hong Kong in April, after 12 years in the role. He has been a vocal champion of human rights and social justice and has often criticised the governments in both Hong Kong and Beijing.