Bilawal Bhutto Zardari, chairman of the Peoples Party, has launched a scathing attack on his political opponents who he said must stop “making excuses” for Taliban violence.

Bilawal also accused Prime Minister Nawaz Sharif and Tehreek-i-Insaf chief Imran Khan of “letting down the people” by not backing firm military action against the Taliban.

“Perhaps they are suffering from Stockholm Syndrome,” he said, referring to cases of hostages who sympathise with or even assist their captors. “There is no reason why the national leaders, the so-called leaders, should not speak out against people who are murdering our citizens, murdering our armed forces and claiming responsibility.”

The remarks are likely to further burnish his reputation as both a brash new arrival on the country’s political scene, but also the most outspoken politician on the issue of militancy and extremism.

The 25-year-old son of former premier Benazir Bhutto said the government’s inaction had been disastrous, emboldening extremists to target civilians, including Malala Yousufzai, the schoolgirl education activist who nearly died in 2012 after being shot in the head by a Taliban assassin. “This is why people like Malala become targets because the politicians, or the so-called leaders of this country, can’t find the courage to speak out when a 16-year-old girl could. If we all speak in one voice, they can’t kill us all,” he said.

Bilawal Bhutto Zardari said he could speak out only because of the vast security operation that surrounds him at all times and heavily restricts his travel. He spends much of his time at his fortress-like family compound in Karachi.

“I have a lot of security - I lost my mother to the Taliban because of a lack of security - and that explains partly why I can be so vocal,” he said. “But so does Imran Khan. Nawaz Sharif is the prime minister of Pakistan, Shahbaz Sharif is the chief minister of Punjab. They all have more security than I do. They have no excuse.”

Imran Khan argues that strident rhetoric might endanger the lives of his supporters and party activists. Bilawal has shown no such caution.

He is firmly against negotiations with the Taliban, saying the time has come for far-reaching military operations against the TTP, particularly in North Waziristan.

But he warned an operation should be in cooperation with Afghanistan, an unlikely proposition given the distrust between Kabul and Islamabad. “With Afghanistan there is no point of us launching an operation over here if they are just going to hop across the border and find sanctuary over there,” he warned. “The ideal situation would be an operation from both sides at the same time.”

Bilawal Bhutto said he was exasperated by the government’s decision last week to hold talks with the Taliban. “It is extremely frustrating, not just for me but for the people who risk their lives on a daily basis, for the people who die on a daily basis.”

By arrangement with the Guardian