The Home Office is a remorseless engine of cruelty, incompetence and Kafkaesque bureaucracy. It cannot be reformed, but should be scrapped. Consider the case of an 85-year-old British citizen – taken up by Labour MP Preet Kaur Gill – who has Alzheimer’s. He has lived and paid taxes and national insurance in Britain for half a century; most of his extended family, as well as grandchildren and great-grandchildren, are British citizens. The Home Office is currently attempting to deport him to India. Or take 40-year-old Alfred Jahn, who told me that he was woken up two years ago by armed police officers looking for “an Albanian”: they’d got the wrong address. He says only after prolonged chasing was a “lacklustre explanation” forthcoming. Or 25-year-old Paige from Enfield, north London, who was saved from jumping from a bridge and sectioned after her Albanian fiance’s visa application was refused in December 2017. She had submitted all the documents proving she met the necessary £18,600 income threshold, but the Home Office ripped the two apart for more than 11 weeks. Her fiance was hospitalised at least 15 times because of the stress; Paige lost her job. It turned out that the Home Office had mislaid a payslip.

Deport as many as you can, with any excuse, by any means: that is the underlying ethos of this morally bankrupt regime

There has never been a Home Office golden age, as the records of past authoritarian New Labour stewards, from David Blunkett – who once demagogically warned of refugees “swamping” local schools – to the bruiser John Reid, testify. But the Tories settled on scapegoating migrants for all the ills of society as a central plank of their political strategy, and the Home Office is the blunt instrument they have used to put it into practice.

The only consistency in Theresa May’s wretched political career is an obsessive hostility to migrants: as one rightwing commentator put it, she is “a remainer who hates immigration”. In the hostile environment, she has proved willing to subordinate the most basic human rights to a fixation with removing and deterring migrants and refugees. It has resulted in people who have lived and worked in Britain legally for decades being kicked out on to the streets, denied urgent medical care and deported from their own country. The compensation scheme for victims of the Windrush scandal, one of the worst injustices committed by British officialdom since 1945, is a bureaucratic nightmare offering derisory amounts. And let’s abandon the pretence that lessons have been learned: the Home Office is now developing a database of migrants to deny them access to essential public services; it’s been quite correctly described as “deeply sinister” by human rights campaigning group Liberty.

Where to even begin with this conveyor belt of injustice? As Liberty has documented, it’s been made impossible for victims of serious violence – from stabbing to rape – to report their crimes because the police routinely hand undocumented victims to the Home Office. Children born in Britain are being charged more than £1,000 to register for British citizenship, around two thirds of which is just profit for the Home Office. Children’s school records are used to obtain their parents’ addresses for immigration enforcement, and children are denied free school meals based on their families’ immigration status. Appeals are obsessively brought against rulings allowing refugees and migrants to stay, even though the Home Office loses nearly three quarters of them after dragging vulnerable people through a desperately stressful process. Refugees are deported to places of danger if they commit minor offences, like Zainadin Fazlie, a father of four British-born children, who was deported to Afghanistan and then killed by the Taliban.

Ripping families apart through incompetence is a Home Office speciality. One mother fears being deported to China – and separated from her British husband and her British-born children – after the Home Office allegedly lost paperwork proving her husband was over the income threshold. This week, a Home Office minister had to apologise to a couple falsely accused of a sham marriage, a mistake costing them tens of thousands of pounds in legal fees and visa applications. And hundreds of children who claimed refuge in Britain have been deported when they have turned 18 to countries the government officially deems too dangerous to visit, such as Afghanistan and Iraq.

Enough. The Home Office is an institutionally broken and unjust organisation; its very culture is rotten. Deport as many as you can, with any excuse, by any means: that is the underlying ethos of this morally bankrupt regime. Just this week, the appeal court condemned the Home Office for its “legally flawed” misuse of a terrorism-related section of immigration law to refuse immigration applications from people who legally amended their tax records. They’re not terrorists, the Home Office knows they’re not terrorists: it is simply exploiting any loophole it can to kick people out of the country.

Rather than wasting time trying to reform this sadistic operation, it should be replaced – perhaps broken up, with domestic policing separated from immigration and asylum – with a new body that respects human rights, rather than subordinating them to an ideology hostile to migrants. That isn’t straightforward, of course. “That rests on the prior question of society agreeing those values,” as Liberty’s Gracie Bradley puts it to me. “As long as society thinks Muslims, migrants and black young people are a problem, it doesn’t matter what the department is called.” So demanding the abolition of the Home Office must be combined with a debate on combatting institutionalised racism and xenophobia. But as the injustices committed by the Home Office multiply, it becomes ever clearer that it cannot be reformed: it must go.

• Owen Jones is a Guardian columnist