By Isabel Reynolds
The letter handover came weeks after Japan's whaling fleet set off for the Antarctic for an annual hunt aimed at catching about 900 whales, which Tokyo says is carried out for scientific research purposes.
In a break with past practice, Greenpeace is focusing on a campaign to try to change Japanese domestic opinion this year, rather than send a ship to chase the fleet in the Southern Ocean, which caused diplomatic ruffles last year.
That decision has drawn criticism from hardline anti-whaling group Sea Shepherd, whose members skirmished with whaling vessels at sea last season.
"Each year we put more and more emphasis on the campaign in Japan," Steve Shallhorn of Greenpeace Australia told reporters. "We are asking the people of Japan to ask their politicians to end the subsidy to this outdated industry," he added.
He and Greenpeace directors from the United States, Brazil, the Netherlands, Germany and other countries, were joined by Paddy Hart, an Australian former whaler, for the letter delivery.
Activists were also set to protest outside Japanese embassies abroad, Greenpeace said.
Japan officially stopped whaling under a 1986 global moratorium, but continues to take hundreds of whales in what it calls a research program. Much of the meat ends up on dinner tables.
Though most Japanese do not eat whale meat on a regular basis, many are indifferent to accusations that hunting the creatures is cruel, while others resent being told what they should eat.
But Greenpeace Japan Director Jun Hoshikawa said there were signs that interest in the issue was rising in Japan, with a handful of lawmakers calling for an investigation of the hunt.
Among them is Ryuhei Kawada, known for battling the government after he and others became infected with HIV through tainted blood products.
"When the government is wrong, it is important to raise your voice," he told reporters. "The United States and Australia have a history of whaling, but Japan continues even now. We should think about this from the point of view of the environment," he said.
An official at the whaling section of Japan's Fisheries Ministry said he could not comment because he had not seen the letter from Greenpeace.
(Reporting by Isabel Reynolds; Editing by Bill Tarrant)