The bill allows heads of ministries and agencies to classify 23 vaguely worded types of information related to defense, diplomacy, counterintelligence and counterterrorism, almost indefinitely.
Critics say it might sway authorities to withhold more information about nuclear power plants, arguing they could become terrorist targets. Or they warn that officials may refuse to disclose key elements of free trade talks to protect concessions that would make Tokyo or a partner look bad.
The move is welcomed by the United States, which wants a stronger Japan to counter China's military rise, but raises fears in Japan that the country could be edging back toward its militaristic past, when authorities severely restrained free speech.
Some experts say the legislation would ease the way for Abe's drive to revise Japan's U.S.-drafted pacifist constitution to give more power to the government and stress civil duties over basic human rights.
"My biggest concern is that it would be more difficult for the people to see the government's decision-making process," said Kyouji Yanagisawa, a former top defense official who was in charge of national security in the Prime Minister's Office in 2004-2009. "That means we can't check how or where the government made mistakes, or help the government make a wise decision."
At a public hearing in Fukushima on Monday, the only one held before the vote, lawyer Hiroyasu Maki said the bill's definition of secrets is so vague and broad that it could easily be expanded to include radiation data crucial to the evacuation and health of residents in case of another nuclear crisis. Opponents said that Tuesday's vote despite unanimous opposition by the seven local officials invited to the hearing already shows the Abe government's high-handed approach.
Ruling Liberal Democratic Party lawmakers say Washington has repeatedly said it feels insecure about sharing top-secret information with Japan due to its lack of legal protection for secrets. The U.S. is worried about leaks to China, they say.
"(The bill) is by all means necessary to step up Japan's intelligence level. Many other countries already have legal frameworks like this but Japan does not," said Nobutaka Machimura, a senior ruling lawmaker and head of the party's secrecy bill team.
Under the bill, leakers in the government face prison terms of up to 10 years, up from one year now. Journalists who obtain information "inappropriately" or "wrongfully" can get up to five years in prison, prompting criticism that it would make officials more secretive and intimidate the media. Attempted leaks or inappropriate reporting, complicity or solicitation are also considered illegal.
"This is a severe threat on freedom to report in Japan," said Lawrence Repeta, a law professor at Meiji University in Tokyo. "It appears the Abe administration has decided that they can get a lot of what they want, which is to escape oversight, to decrease transparency in the government by passing a law that grants the government and officials broad authority to designate information as secret."
Currently, each Japanese ministry has its own rules to protect secrets, including "defense secrets" decided by the Defense Ministry. The proposed legislation would complement a separate bill, also due to be passed this week, to establish a National Security Council that would centralize the chain of command in the office of the prime minister and give him more power.
Washington sees the proposal as a positive step that would make Japan a "more effective alliance partner," U.S. Charge d'Affairs Kurt Tong said in a recent speech. He urged Japan, however, to make the process transparent and to explain the policies to its Asian neighbors.
Yanagisawa says he does not recall any instance in which Japan failed to obtain necessary information from Washington or other countries due to the lack of a secrets law. When the U.S. or other countries decided not to share information with Japan, it was because of their own national interest and not because of Japanese secrecy protections, he said.
Even without the new secrecy law, journalist Takichi Nishiyama, 82, was convicted of exposing confidential cables related to a secret deal with Washington involving the return of U.S.-administered Okinawa to Japanese control in 1972.
Nishiyama said what he revealed was only a tiny part of the mountain of secrets that never surface. The government newly classified more than 70,000 sets of defense secrets over the past seven years, but some 40,000 others were destroyed about 10 percent of the classified information Japan has.
"In this country, it's already difficult enough to get information to verify our own history," Nishiyama said. "The new law would only make it worse."
Opposition lawmaker Akihisa Nagashima said Japan's secrecy law is designed in favor of the government's secrecy protection, while ignoring record keeping and disclosures to the public compared to the U.S. system. Japan's proposed law also designates the prime minister as a third-party overseer.
Japanese and foreign journalists, writers, academics and activists have opposed the bill.
According to the result of a government-sponsored "public comment" process in September, 77 percent of about 90,000 comments opposed the bill, most of them expressing concerns about the possibility of their civil activities being curtailed.
Some people worry that the law might point Japan back toward the severe restrictions on freedom of speech and press imposed before and during World War II. Under the Maintenance of the Public Order Act of 1925, some 100,000 people were arrested.
Activist Kazuyuki Tokune says his attempts to access information about nuclear power plants may be considered illegal under a broad interpretation of the law.
"I may be arrested some day for my anti-nuclear activity," Tokune said during a protest against the secrecy bill outside the Prime Minister's Office. "But that doesn't stop me."
