Their second-hand fishing boat, the Diaoyu Island II, will set sail on August 12 or 13, depending on the weather and the state of the vessel's mechanics.

Last year, the boat stopped in Taiwan but no break is planned for next month's voyage to the eight uninhabited islands in the East China Sea, claimed by the mainland, Taiwan and Japan, which calls them the Senkaku Islands.

Committee chairman Raymond Chan To-wai said the date was chosen to remind the Japanese of the suffering inflicted on the peoples of Asia during the second world war.

'As an aggressor in the war, Japan has not admitted its responsibilities, and we are telling them we have not forgotten,' Mr Chan said. Although the committee would not reveal the trip's sponsors, members said the HK$250,000 cost of the voyage was being covered.

Veteran activists, including the group's former chairmen, Albert Ho Chun-yan and Or Wah, are unlikely to join August's expedition. Mr Chan said most of the passengers would be from the younger generation. Tsang Kin-sing, another veteran activist, said: 'We want more youngsters to join and experience reclaiming sovereignty on Chinese soil.' Seats would also be reserved for activists from the mainland, Taiwan and the United States, Mr Chan said.

'Safety is our major consideration,' Mr Chan added. 'But we will try to land on the islands as long as we have the fuel to get back.'