The hoarseness did not prevent him from railing against overzealous officials in the Security Bureau and the Immigration Department, 'communists' in Beijing, 'communists' friends' in the SAR and their 'united front' tactics.

'The whole thing is in the hands of Immigration and the Security Bureau. They are overdoing it,' the coadjutor bishop of the Catholic Diocese in Hong Kong told the South China Morning Post. 'And other officials of Government just keep quiet.'

He had earlier called on Chief Executive Tung Chee-hwa to speak out, accusing him of a 'conspicuous silence' on the issue. His comments could also be viewed as indirect criticism of Chief Secretary Donald Tsang Yam-kuen, a devout Catholic, who also has remained silent.

Bishop Zen, the second most senior cleric in Hong Kong, who is expected eventually to become the local Church's head, is no stranger to controversy.

He berated Mr Tung in February for branding the Falun Gong an 'evil cult', and questioned whether the Catholic Church could be next as its bodies had also been involved in peaceful protests.

The Shanghai-born bishop has been branded a 'Vatican agent' by the Mainland Religious Affairs Bureau, which refuses to recognise the Holy See in Rome, and has been banned from visiting the mainland since 1998.

When Beijing's officials in Hong Kong asked the Church to keep low-key celebrations for the canonisation of 120 Chinese and foreign saints - which was viewed by the mainland as a gross insult because they were either foreign missionaries or described as Chinese martyrs - about 1,200 people attended a service at the Caine Road cathedral.

The local Church's head, Cardinal John Baptist Wu Cheng-chung, infuriated the SAR Government in June 1999 when he wrote an open letter criticising its decision not to grant right of abode to mainland children born to Hong Kong parents.

Relations between the Vatican, its Hong Kong diocese and the mainland Government appear to have been troubled since Beijing rejected in 1999 the possibility of Pope John Paul visiting the SAR. The Holy See's relations with Taiwan, rather than the People's Republic, were cited as the reason.

The activism of the Catholic Church hierarchy on local issues has emerged only in the past few years, after Hong Kong's return to Chinese rule, and follows what observers describe as 25 years of virtual silence.

Considering that the Church - with its allegiance to the Pope in Rome - is banned on the mainland and owes its survival in the SAR to the 'one-country, two-systems' policy, questions are being raised about whether it is courting danger by confronting authorities.

'The Catholic Church worldwide used to be rather conservative and we believe in hard work in silence,' Bishop Zen said.

'Maybe in the years under the colonial regime we had things not always according to our way, but they were still acceptable.'

He says his approach is a product of his training in the early 1960s, when the Second Vatican Council ushered in a more liberal mindset.

'After the handover, we have more reasons to be concerned about what is happening. For those who know the communist system, we know you can't have full trust in their promises,' Bishop Zen added with a laugh. 'Maybe my formation and character leads to this being more outspoken.

'[However], you should not attribute this to me but the Church. We think we have to speak out on important issues.'

Bishop Zen does appear to have the approval of his parishioners to take a vocal line.

A meeting of the diocesan synod last year urged the Church to condemn injustice. 'Church leaders should speak up on social justice or influential social events when appropriate, acting as a social conscience and moral force,' it said.

Bishop Zen does not believe the Church could come under concerted, official pressure in Hong Kong as a result of its activism, citing Beijing's promise of religious freedom under the 'one country, two systems' principle.

'That was a very solemn promise. I don't think they are so stupid as to change that,' he said. 'That would have international repercussions. The whole world is watching. I don't think there is any danger on that part.'

However, Bishop Zen concedes that there are subtle ways of exerting pressure. He is no longer invited to dinners by Beijing's Liaison Office and there is the ban on him travelling across the border. When Mr Tung went on stage at the Convention Centre last week to announce he would seek a second term as Chief Executive, Buddhist leaders and Anglican archbishop Peter Kwong Kong-kit were there. No Catholic bishop was present.

Hong Kong Human Rights Monitor Law Yuk-kai is worried that the Church may soon become the victim of a 'united front attack'.

'They have the tactic of isolating the worst enemy and getting support of lesser enemies to attack them,' Mr Law said.

The Church could also find the SAR Government no longer consults it or see itself overlooked when representatives are being appointed to various bodies. It might also find funding for schools drying up, he said.

Catholics were intentionally taking a more independent line on political and social issues, putting Christian principles ahead of maintaining a good relationship with the Government as it had in the past, said Professor Lo Lung-kwong, who is currently a visiting scholar at the Harvard Divinity School.

'To make the differences more obvious and public [produces] the result of a clearer identity for the Church,' said Professor Lo, head of theology at the Chinese University of Hong Kong.

'In the past, the close and good relationship between Church and government has been perceived and taken for granted by people in Hong Kong. Under a new and different political situation, it may be better to clear up the old image and create a new one.'

The latest controversy arose when it was revealed 187 mainland children, granted a temporary stay in Hong Kong while awaiting the outcome of applications to remain, had been prevented from going to school because officials considered them 'visitors'.

Bishop Zen wrote to the heads of all 300 Catholic schools asking them to admit the children if they had room, prompting the Government to warn that any school admitting them without approval could be committing a crime. The cleric then said the Church could resort to civil disobedience.

The barred children and their supporters appeared to have won a partial victory on Monday when the Security Bureau promised to review their cases. 'They backed down to a certain degree. That was very good,' Bishop Zen said.

Glenn Schloss is a staff writer for the Post's news desk.