Najam Sethi, the star of one of Pakistan's top rated political chatshows, does not travel far to work. For the three nights a week his programme is on air, Sethi simply opens his bedroom door and walks into a purpose-built studio.

Since January the veteran journalist has been broadcasting from the glossy, little studio because he fears his public criticism in Aapas Ki Baat (Just Between the Two of Us) of one of Pakistan's most powerful institutions could get him killed.

He is not alone. Last month the prominent human rights lawyer Asma Jahangir, who lambasts the military for interfering in civilian politics, claimed there was a plot to kill her hatched "at the highest level of the security apparatus". She has since been given government guards to protect her.

Almost alone among the country's army of TV pundits, Sethi regularly takes on the Inter-Services Intelligence Directorate (ISI), the military spy agency accused of everything from supporting the Taliban insurgency in Afghanistan to murdering its critics. Few other Pakistani journalists dare make such claims, or even criticise the Pakistani army's long history of interfering in the affairs of the nation.

A staple of Sethi's show is raking over the history of "failed military strategies, lost wars, misadventures and coups" by Pakistan's generals.

Sethi began to feel seriously concerned for his safety after the US raid on Osama bin Laden's compound last May, after he told his audience Pakistan must have been "complicit or incompetent" during the al-Qaida chief's decade-long stay in the country.

The broadcast led to a "stormy" face-to-face confrontation with a very senior ISI official. "He accused me of everything, anti-Pakistan, anti-army, anti-everything," Sethi said.

Weeks later the journalist Saleem Shahzad, who wrote extensively about the Taliban, al-Qaida and the ISI, was found dead in a canal. Sethi told viewers Shahzad had been tortured to death by the ISI.

With the top brass apoplectic, high-level government officials warned Sethi his name had been circulated on a hit list. A kidnapping plot, he was told, had been hatched involving two militant groups with links to the ISI.

Militant groups have pulled off some audacious kidnappings of high-profile people in Lahore, including Shahbaz Taseer, son of the assassinated former governor of Punjab province, who has not been seen since he was hauled out of his car in an upmarket area of Lahore in August.

Sethi and his wife, the journalist Jugnu Mohsin, hoped the danger would die down if they left the country. After four months abroad, Sethi returned to find he was still at risk, despite going public about the threats against him.

"On the first programme I did when I came back, I said I had been facing threats from state and non-state actors," he said. "And I warned that if anything should happen to me or my family we would hold the military establishment at the highest level responsible."

Security cameras now cover his house, which he rarely leaves. Soon he will have an armoured vehicle for his occasional forays into the city. Trusted guards from Mohsin's ancestral village have been drafted in to keep an eye on the guards provided by the government.

Sethi's liberal politics show, generally out of step with a society that appears to be turning more conservative, has been a surprise hit on the country's most popular private channel and commands primetime advertising rates, despite going out at 11pm. With a hit on their hands and nightly journeys to the Lahore studios of Geo TV thought to be too dangerous, channel bosses took the unprecedented step of building their star a studio in the couple's old bedroom.

Sethi sits at a glass table in the middle of the blue and yellow set and discusses the day's news with co-host Muneeb Farooq. With Pakistan buffeted by what seems to be at least one scandal, disaster or political upheaval a week, there's always a lot to talk about.

While the programme is slick, the makeshift broadcasting facilities are anything but. The production team run the show from monitors and laptops inside a battered pink and white Toyota Coaster in the driveway. They work in cramped, uncomfortable conditions – even at 11pm when the show begins, temperatures in Lahore are sweltering.

"Logistically it is a nightmare," said Zeeshan Khan, the producer. "If it rains, basically we can't broadcast."

As the show goes out Mohsin sits next door on their bed watching the broadcast, the sound turned down so that it doesn't disturb her husband just a few metres away.

Sethi receives ample abuse on the internet for his efforts, with people accusing him of being a US spy or of being corrupt. Recently his name appeared among a list of journalists allegedly paid off by a billionaire real estate tycoon. He denies the claims and sees it as part of a "fully fledged campaign" by military intelligence to undermine his credibility. He is more concerned about the threats. "In thirty years of English journalism, I got maybe three threats," said Sethi, who still edits The Friday Times. "But in three years in television I get one or two threats every day."

Nadeem Farooq Paracha, a cultural commentator for the Dawn newspaper, said Sethi's value lay in his political predictions, which usually turned out to be correct – and the fact that "he does not follow the usual rightwing, populist narrative of the rest of the Urdu media".

He also challenges the "military establishment's Orwellian distortions of history", that Paracha says airbrushes great fiascos such as the 1971 war that led to the breaking away of East Pakistan and the formation of Bangladesh.

"The army have started to realise that with him being on such a mainstream channel with such a huge audience he is starting to influence a lot of people, young minds particularly," Paracha said.

Sethi takes the threats as a sort of backhanded compliment, a sign that he must be doing something right and relishes the clout the show has given him. He said: "I can't go back to newspapers now. I'm not interested."