NEWS junkies in Mexico have woken up feeling bereft and baffled since March 16th. The feisty, staccato voice of Carmen Aristegui, a radio anchorwoman with almost cult status, especially among left-leaning listeners, has gone off the airwaves after a public row with her employer, MVS Radio. The radio group fired her despite acknowledging that she was one of Mexico’s most popular morning-show hosts, drew in advertisers and delivered scoops that scandalised the country. Even MVS Radio sounds remorseful. “It’s a situation in which everyone loses,” a spokesman admits.

Behind this falling out are problems that systematically undermine journalism in Mexico, where the media have long been dominated by political power. Many outlets, including MVS Radio, rely on the government for advertising and other perks. The biggest television networks, Televisa and TV Azteca, are a pliant duopoly.

Ms Aristegui, though an MVS Radio employee, cast herself as the antithesis of that system, picking fights—often backed by impressive research—with the most powerful. In November her team of investigative reporters broke a story that President Enrique Peña Nieto’s wife was buying a $7m mansion mortgaged to her by one of the government’s preferred contractors, which has damaged the president’s credibility. Last year one of her reporters revealed an alleged prostitution ring set up by the head of the ruling Institutional Revolutionary Party (PRI) in Mexico City. In 2011 she suggested on air that the then-president, Felipe Calderón, was an alcoholic (for which she was temporarily fired).

Such stories, plus opinions delivered so passionately that she often talked through commercial breaks, have won her fans. “People adore her,” says Enrique Krauze, a Mexican historian. Her indignation is selective. Guests on her show who rail against Mr Peña’s energy reforms or praise Venezuela’s left-wing president, Nicolás Maduro, are rarely challenged. “This is a country where individuals have too much weight and institutions too little. She is a journalist caudillo,” Mr Krauze says.

Now MVS Radio has made her a martyr for press freedom. It insists that Ms Aristegui lost her job because she twice broke company rules. First, she pledged MVS Radio’s support for a citizen-journalism project called Méxicoleaks without consulting the company. Then she publicly threatened to go off air if two of her colleagues fired over the Méxicoleaks kerfuffle were not rehired. Saying it does not accept ultimatums, MVS Radio sacked her instead.

Few believe that is the whole story. Despite its fury over the alleged insubordination, MVS’s logo remained on the Méxicoleaks website for nearly a week. Two days before it fired Ms Aristegui, the company issued guidelines restricting anchors’ editorial autonomy and their ability to undertake investigative projects. That appeared to have little to do with Méxicoleaks.

The timing raises the suspicion that the government—which is struggling to regain popularity less than three months before mid-term elections—has put pressure on MVS Radio. Her sacking came a few weeks after Mr Peña promoted Eduardo Sánchez, a former lawyer for the parent company, to be head of the government’s communications. MVS Radio emphatically denies any link. The government says it hopes both sides will resolve their differences. But no Mexican government has resisted the temptation to use advertising and other forms of leverage over the press, whatever the toll on freedom of expression. If Ms Aristegui wants to avoid that, she may have to become a media baron herself.