As the emperor's plane touched down in London last night, 20 civilian prisoners held a candlelight vigil outside the Japanese embassy. Wearing sashes saying ``prisoners of Japan 1941 to 1945 - compensation overdue'', they handed out leaflets urging the emperor to acknowledge the guilt of the past.

``Now is the time to atone for the sins of your father emperor Hirohito under whose direct orders we the British civilian prisoners of the Imperial Japanese forces in the Far East, suffered death, torture, inhumanity, degradation and destitution,'' the leaflet said.

But a senior Japanese diplomat earlier reiterated that while the emperor understood their feelings, being a nonpolitical monarch, there was no way he could apologize.

Prime minister Tony Blair urged his countrymenlast night to give the emperor a warm welcome. He said his visit should be seen as ``an opportunity to celebrate a strong, modern, relationship between former enemies who are now close allies on so many issues''.

Veterans' organisations, however, said at least 1,000 prisoner-of-wars would demonstrate, their backs turned, at the official welcome on Tuesday. The demonstrators plan to whistle an allied tune, ``Colonel bogie'' when Akihito, 64, rides down the mall in a horse-drawn carriage with the Queen to Buckingham palace. Emperor Akihito, who was a child when Japanese armies rampaged through Asia, had attended Queen Elizabeth's coronation in 1953. He has visited Britain four times since then.