Britain plans to deport a prominent Pakistani activist within a week, even though he has received multiple death threats from the country’s most brutal sectarian group, and from Taliban militants who know his home address and have been stalking him online.

Liaquat Ali Hazara is a campaigner for a Shia minority group that shares his name, the Hazaras. More than 500 Hazaras have been killed in his home province of Balochistan since 2008, according to a Human Rights Watch report published this year, entitled We Are the Walking Dead.

It details bombings and shootings, including an assault on a bus full of pilgrims, when gunmen came back to kill wounded survivors as they were taken to hospital. “There is no travel route, no shopping trip, no school run, no work commute that is safe,” the report said.

The UK government has scheduled Hazara’s deportation for 21 October on the grounds that he would be safe in other parts of the country, he told the Guardian. But they still plan to fly him to Quetta, the Balochistan capital and his hometown, where threatening letters have been hand-delivered to the house where his wife and parents live. He worries he may not even make to his front door.

“The threatening letters that were sent to my home say very clearly if I don’t stop talking against the extremist groups or if I come back to Pakistan they will behead me,” Hazara said in a phone interview from the detention centre where he is being held.

“I fear they can just “disappear” me from the airport, because they have good contacts with the security people as well, who have been infiltrated by the religious extremists.”

Even if he does survive the journey, it is not clear where he might go if he left his job. There have been sectarian killings across Pakistan, and some of the emailed death threats have been traced to Karachi, a port city several hundred miles away from Quetta, and Hyderabad, another distant town.

“We will deal with you the same way as we do with your people in Quetta, who are sent to hell,” someone using the name Abdul Haq Jhangvi wrote to him in 2011. “We have decided to catch you alive, then, we will send your head [to] your people. We will teach you a good lesson so that no other person dares to write against the Taliban mujahideen. We will see you very soon.”

Hazara relatives attend the funeral ceremony of victims who were killed in a suicide bomb attack in Quetta this month. Photograph: Jamal Tarakai/EPA

Hazara, 36, was studying for an accountancy diploma in London when his concerns about rising sectarian violence pushed him to begin campaigning in 2009.

Outside the region, the scale of the killings is not well known and there is little pressure on Islamabad for change, while the Pakistani government has seemed largely indifferent to the steadily rising toll.

After the attack on the bus of pilgrims in 2011, the provincial chief minister, Aslam Raisani, said: “Of the millions who live in Balochistan, 40 dead [in this attack] is not a big deal. I will send a truckload of tissue papers to the bereaved families.”

Determined to try to change those attitudes, Hazara founded the Hazara United Movement, a political campaign group, organising protests and sit-ins, writing op-eds and running a campaigning blog. Among other achievements, it helped lay the ground for a House of Commons debate this year on the situation in Balochistan.

His work did not go unnoticed at home, however. The first threats from the Taliban and Lashkar-e Jhangvi, one of Pakistan’s most vicious Sunni militant groups arrived in 2010 and 2011. After a string of emailed warnings in English, and handwritten threats in Pashtu and Urdu, Hazara claimed asylum in September 2012, based on his high-profile political activities.

His first barrister failed to present the immigration tribunal with information he had prepared detailing how the threat to his life extended beyond Quetta, Hazara said. Two subsequent reports from a legal expert were rejected by the Home Office as insufficient grounds for asylum, he says, and he was refused a request for a judicial review of the case.

“My life is genuinely in danger, and the Home Office is not listening,” said Hazara, who has been in detention since July with deportion set for next week. “I would like to request Human Rights Groups to campaign for me and exert more meaningful pressure.”