A plan by former Air Self-Defense Force chief Toshio Tamogami to deliver a speech in Hiroshima on the day it remembers the U.S. atomic bombing in 1945 is an "act full of malice" being conducted in the name of freedom of speech, a former Japanese diplomat has written.

Tamogami was sacked last year when it was learned he had written a prizewinning essay justifying Japan's militarist past and colonialism.

In a recent essay, Naoto Amaki, a former ambassador to Lebanon, wrote: "It's not too late yet. The government, intellectuals, citizens, supporters of the Constitution, proper rightists who love the country, everybody should join hands by going beyond their positions to postpone Mr. Tamogami's speech in Hiroshima planned on Aug. 6 for the sake of Japan."