Opposed by legislators Chim Pui-chung and Tam Yiu-chung, the letter also will urge Britain to ask China to clarify the definition of ''state secrets'' and to issue guidelines so Hong Kong reporters covering the mainland would know the rules.

The sentence of 12 years in jail plus the deprivation of political rights for two years was upheld by the Beijing Municipal Higher People's Court.

A court spokesman said: ''It was made public this morning that the Beijing Municipal Higher People's Court supported the original decision of the Beijing Intermediate People's Court after considering all the relevant facts and evidence.

''It's final.'' About 200 people were in the court when the decision was announced at 9.30 am. Xi, 38, was given a copy of the appeal result before being handed over to the reform-through-labour authorities to begin his sentence.

The state-run television service carried footage of the court hearing last night.

Looking dispirited and tired, Xi and co-defendant Tian Ye were held from behind by uniformed bailiffs. Both wore civilian clothing and stood with their heads bowed.

The announcer called the case against them ''very grave''.

Last night Xinhua (the New China News Agency) issued a report on the court decision. It revealed for the first time the identity of bank official Tian, who was sentenced to 15 years for supplying Xi with the secret documents.

The report said Tian was a former deputy head of the foreign-affairs department of the People's Bank of China.

It gave more details on the ''state secrets'' Tian had stolen. They included samples of new banknotes, a ''strictly confidential situation'' regarding the selling of gold by China in the world market, the adjustment of exchange and savings rates and the plan to raise interest rates.

The report also said Tian had stolen a document titled ''Provisional regulations on the trading of renminbi by foreign-funded financial institutions'', which was marked ''confidential''.

He had passed the documents to Xi for publication in the Hong Kong newspaper Ming Pao, causing huge losses to the national economy, Xinhua said.

Xi's father, Xi Linsheng, who suffered a heart attack after hearing of his son's verdict this month, did not attend yesterday's court hearing.

He said he wanted to find out as soon as possible to which prison his son had been sent.

Ming Pao officials said in a statement last night that they were ''deeply grieved and outraged by the decision''.

They said the two lawyers from the Jingtian Lawyers' Firm in Beijing who were defending Xi had decided to argue for Xi's innocence after studying the record of the case and meeting Xi.

''They [the lawyers] contended that the court should quash Xi's conviction on the grounds that there was not sufficient evidence on which to convict Xi, that the facts of the case had not been ascertained, and that the court of first instance misapplied the laws,'' the statement said.

''We are convinced that they came to the correct conclusion . . . that what Xi had done before he was arrested was just what a reporter on assignment in China would do in the line of duty.

''We will keep in touch with Xi's family and his counsel and will continue to seek ways to have the unjust verdict against him reversed on the basis of his counsel's arguments for his innocence,'' the statement said.

Ming Pao group chairman Yu Pun-hoi said it had no idea where Xi was serving his sentence. He said the court might not have fully studied all the legal points before rejecting the appeal.

The lawyers could not be reached for comment.

In a rare move, Ming Pao merely carried a 20-character editorial today, saying ''Salute to our reporter Xi Yang, throw away pens for China's judicial system.'' The chairman of the Hong Kong Journalists' Association, Daisy Li Yuet-wah, said her members regretted the decision.

In a statement, the association said Xi's trial had not been held in accordance with law and was unjust.

It said many details remained unclear, and suggested the swift conclusion of the case ''made one feel that . . . the appeal is just a show''.

The association said it would consider calling on the National People's Congress Standing Committee to set up a special team to conduct a full investigation of the case.

A British Embassy spokesman in Beijing said it could not comment because it had not been informed officially by China of the outcome.

A deputy director of Xinhua, Zhang Junsheng, confronted by a group of Ming Pao reporters petitioning against Xi's jailing, also refused to comment last night on the Beijing decision.

However, he maintained that the court had delivered its judgment according to Chinese law.

He reiterated that the case was an individual case and had nothing to do with the press freedom in Hong Kong.

''It is not a question of the freedom of the press, it is a question of the breaking of the law on the mainland when one is carrying out the job of reporting,'' he said.