SYDNEY, Australia — Australian news outlets from across the political spectrum, including Rupert Murdoch’s tabloids, united on Monday to protest the country’s encroaching secrecy laws. Newspapers ran redacted articles on their front pages in a show of solidarity, and online and on the air, prominent journalists called for change.

“When government keeps the truth from you, what are they covering up?” was the question that ran on the cover of newspapers including The Australian, owned by Mr. Murdoch; the liberal Fairfax newspapers; and smaller city and rural newspapers. The question was accompanied with lines of text that had been heavily blacked out.

The campaign is intended to pressure the federal government to change laws that threaten jail time to certain whistle-blowers and journalists, and which allow the authorities to withhold information that is often unrelated to matters of national security.

The laws fall under an umbrella of secrecy that consecutive Australian governments have created over nearly two decades. No other developed democracy has as strong a stranglehold on its secrets as Australia. For years, governments on both sides of the political aisle have granted law enforcement and intelligence agencies more powers, and diminished those of its citizens. Australia is also a democratic nation without a Bill of Rights.