The venerable BBC has been under fire from Conservative party figures in Britain on a range of issues from its coverage of climate change and the Middle East to accusations it downplayed a poll of people saying local government services had improved despite savage budget cuts. Here in Australia, Prime Minister Tony Abbott has led the charge against the ABC, accusing it of lacking patriotism and taking anyone's side but Australia's on controversial issues.

But these are minor skirmishes compared to the war unleashed in Japan on the respected NHK by Prime Minister Shinzo Abe, elected 15 months ago.

NHK stands for Nippon Hoso Kyokai (Japan Broadcasting Corporation). It is a publicly owned company that dates back to 1924, just two years younger than the BBC and eight years younger than the ABC. Under Japan's post-war constitution, freedom of the press is guaranteed, and broadcasting legislation guarantees, in theory at least, NHK's political and financial independence.

Like the ABC until 1975, NHK does not rely directly on the government for its funding, its revenue coming from license fees charged for radio and television reception.

It is effectively at arm's length from the government, especially in regard to its editorial processes, but the government does appoint its 12-member board of governors, with the approval of parliament.

NHK has a well-deserved reputation for impartiality, and is one of Japan's most trusted institutions. It is where people immediately turn to for information during times of crisis, such as in 2011 when Japan was hit by earthquake, tsunami and nuclear meltdown. It is also hugely influential, operating 54 television stations throughout the country as well as two ground-based channels, two satellite channels, three radio channels and an international outlet.

But it is precisely NHK's impartiality that has concerned Mr Abe and his Liberal Democratic Party since they were swept into office at the end of 2012. The prime minister and his immediate circle have expressed concern at Japanese media reporting of key issues, especially the territorial dispute with China over a group of offshore islands and the nuclear power issue post-Fukushima.

Last year, Mr Abe brought in a draconian new state secrecy laws that are already affecting news reporting in Japan. Journalists' traditional access to government officials, other than through formal controlled channels, has been cut with officials facing up to 10 years in jail if they disclose information their agency or its minister deems to be secret. In addition, journalists themselves face prosecution and up to five years in prison if senior government officials deem their news gathering methods ''inappropriate''.

But the hobbling of NHK does not end there. Mr Abe hand-picked a close friend, Katsuto Momii, who has no previous experience in broadcasting, as NHK chairman, and a new board of governors, most of whom have close ties to Mr Abe or his allies.

In January, Mr Momii waded into controversy, defending the Japanese army's use of ''comfort women'' during World War II - a view intriguingly in line with Mr Abe's own revisionist views of Japan's past. The government defended Mr Momii, but he was eventually forced to retract under sustained criticism.

Akihiro Ohata, secretary general of Japan's main opposition, the Democratic Party of Japan, was quoted as saying Mr Momii's remarks were improper and biased, adding he was worried about the broadcaster 's future.

But no sooner had Momii retracted than he ignited another firestorm, declaring that NHK's foreign news coverage should support government policy on controversial issues such as the Senkaku/Diaoyu islands dispute with China.

Japanese media also reported that Mr Momii called an extraordinary board meeting on January 25, the day he began the job, and told the directors to give him their resignations - undated documents that enable him to dispense with them at his whim.

The ABC, in comparison, is on slightly surer ground, but for how long? Attacks on public broadcasters - and by implication, on the public's right to know and access information - have profound implications for political discourse and the health and vitality of democracy. We can only hope Mr Abbott is not emboldened by Mr Abe's assault on public information.

Dr Norman Abjorensen, of the Australian National University's Crawford school of public policy, is a board member of the Asia Media Directory, which audits the status of media in the Asia-Pacific region. In 2012-13, he was visiting professor of international public policy at Hitotsubashi University in Tokyo.