CHINESE doctors are working urgently to save critically ill Nobel Peace Prize laureate Liu Xiaobo, as the government hardened its position against growing pleas to allow China’s best-known political prisoner to leave for treatment overseas.

A stark update issued by Liu’s hospital said he was suffering from poor kidney function and bleeding in the liver from metastasising tumours.

It heightened pressure on Beijing, which has resisted appeals from several nations to let Liu and his family go.

Foreign ministry spokesman Geng Shuang asked other countries at a daily news briefing “to respect China’s national sovereignty and refrain from interfering in its domestic affairs due to an individual case”.

Yesterday the office of German Chancellor Angela Merkel asked Beijing for a “signal of humanity for Liu Xiaobo and his family”.

Liu’s health has been the subject of international attention after news emerged in late June that the dissident had been transferred to a Chinese hospital because of late-stage liver cancer.

Supporters and Western governments urged China to allow him to choose where he wanted to be treated and to release him.

Beijing has so far resisted, citing Liu’s fragile health and arguing that he is receiving the best possible care in China.

Liu was convicted in 2009 of inciting subversion for his role in the “Charter 08” movement calling for political reform.

He was awarded the Nobel Peace Prize a year later while in prison.

Two foreign doctors who were permitted to visit Liu last weekend said on Sunday that they deemed him strong enough to be evacuated, apparently contradicting Chinese expert opinion.

Chinese leaders face two unpalatable choices, analysts say.

If China sends Liu abroad, he could speak out against Beijing in his remaining days and become a worldwide media icon.

If Beijing maintains the status quo — keeping him under close guard in China — his death in custody would tarnish the Communist Party’s image.