China decided that it had no choice but to "spill some blood" during the Tiananmen Square massacre in order to preserve stability, a new memoir by a top leader of the time has claimed.

The phrase, attributed to China's then paramount leader Deng Xiaoping, appears in a previously suppressed diary which publishers say will lift the veil of secrecy over how the decision was made to send in the tanks on the night of June 3-4.

Leaked extracts of the diary said to be by Li Peng, the hardline former head of China's government in 1989 who is most deeply associated with the bloody crackdown, appeared yesterday as dissidents commemorated the 21st anniversary of the Tiananmen Square.