A proposed state secrecy law in Japan that imposes stiffer penalties on bureaucrats who leak information ' and journalists who seek it ' is spurring a public outcry, with opponents blasting it as a heavy-handed effort to hide what the government is doing and restrict press freedom.

The public's top concern is that the government won't say exactly what it wants to make secret. Critics say the law could allow the government to withhold information about whatever it wants and ultimately undermine Japan's democracy.

The ruling party says the "secrecy protection" law, which the lower house of parliament could vote on as soon as Tuesday, is needed to allow the United States and other allies to share national security information with Japan. Along with the creation of a U.S.-style National Security Council in his office, it's part of an effort by Prime Minister Shinzo Abe to beef up Japan's role in global security, and make a more authoritarian government at home.

The moves are welcomed by the United States, which wants a stronger Japan to counter China's military rise, but they raise fears in Japan that the country could be edging back toward its militaristic past, when authorities severely restrained free speech.

"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 at the Prime Minister's Office from 2004-2009. "That means we can't check how or where the government made mistakes, or help the government make a wise decision."

The bill allows heads of government ministries and agencies to classify information related to defense, diplomacy, counterintelligence and counterterrorism, almost indefinitely.

Critics say that 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.

At a public hearing in Fukushima on Monday, the only one held by the government just before the planned 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 the residents in the case of another nuclear crisis.

Ruling Liberal Democratic Party lawmakers say Washington has repeatedly said that they feel insecure about sharing top security 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 levels. Many other countries already have legal framework 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 a prison term of up to 10 years, up from one year now, if convicted. Journalists who get information "inappropriately" or "wrongfully" can get up to five years in prison, prompting criticism that it would only make officials to be more secretive and intimidate the Japanese media.

"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."

Experts including Repeta say the new law paves 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.

Currently, Japan lacks a comprehensive legal framework to protect state secrets except for "defense secrets" that the Defense Ministry is allowed to decide. The proposed bill would complement a separate law, 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 "more effective alliance partner," U.S. Charge d'Affairs Kurt Tong said in his recent speech in Tokyo. He urged Japan, however, to make the process transparent and to explain the policies to its Asian neighbors.

The former bureaucrat, Yanagisawa says he does not recall any instance Japan failed to obtain necessary information from Washington or other countries due to lack of secrets law. When the U.S. or other countries decide not to share information with Japan, it was because of their own national interest not because of Japan secrecy protection, he added.

Even without the new secrecy law, journalist Takichi Nishiyama, 82, was convicted for exposing confidential cables related to Tokyo's secret deal with Washington over the reversion of U.S.-administered Okinawa to Japanese control in 1972.

He said what he revealed was only a tiny part of the mountain of secrets that never surface. He said that most classified Japanese military or diplomatic documents often come out of U.S. archives, not Japanese.

"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."

Japanese and foreign journalists, writers, academics and activists have opposed the bill. On Thursday, about 10,000 people gathered at a Tokyo park to protest the bill.

According to the result of government-sponsored "public comment" process in September, a policymaking procedure similar to public hearing, 77 percent of about 90,000 comments opposed the bill, most of them expressing concerns about a possibility of their civil activities being curtailed.

Some people worry that the law might point Japan back toward severe restrictions on freedom of speech and press imposed before and during World War II. Under the Maintenance of the Public Order Act in 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 recent protest against the secrecy bill outside the prime minister's office. "But that doesn't stop me."