China's cancer-stricken Nobel laureate Liu Xiaobo is in a critical condition as his tumour has grown and his liver is bleeding, the hospital treating him said Monday.

Doctors have informed the family that they are preparing for the possibility of taking the 61-year-old democracy advocate into emergency care if necessary, the First Hospital of China Medical University in the northeastern city of Shenyang said in a statement.

Meanwhile Britain and the European Union have joined a growing chorus of voices calling for China to completely free its most famous political prisoner, the dying Nobel laureate Liu Xiaobo.

A spokesperson for the British embassy in Beijing said Britain had “repeatedly expressed serious concern at the treatment of Liu Xiaobo by the Chinese authorities”.

“We continue to urge the Chinese authorities to ensure Liu Xiaobo has access to his choice of medical treatment, in a location of his choice, and to lift all restrictions on him and his wife Liu Xia,” the spokesperson added.

A spokesperson for the EU delegation in Beijing said it had discussed the activist’s case with the authorities and asked “that China immediately grant Mr Liu parole on humanitarian grounds and allow him to receive medical assistance at a place of his choosing in China or overseas.”