Boris Johnson took his disinformation campaign to the BBC on Sunday with a blizzard of bluster, obfuscation and lies designed to blunt any interrogation. He lowered the bar for political debate by cynically exploiting the terrorist attack on Friday to peddle a plan for draconian sentences, against the wishes of a dead victim’s family; then by bizarrely blaming the opposition parties for the release of a terrorist (he was let out because of the sentence imposed by the court of appeal); and last by attempting to smear Jeremy Corbyn with a conspiracy theory about him wanting to disband MI5.

Mr Johnson, because he is prime minister, has better access to the details of the case of Usman Khan, a terrorist who murdered innocent people in London last week, than almost anyone else. He knows where he was detained, and what restrictions there were on his movements. He would know what the police and counter-terrorism officers were doing to monitor Khan. But Mr Johnson’s eye is not on the facts to inform the public. Mr Johnson does not care a jot about whether what he says describes reality. This is why he makes facts up. The act is a sinister distraction.

Mr Johnson is attempting to distance himself from his party’s grinding destruction of the justice system in England and Wales after nine years of austerity and outsourcing. Only last year the chief inspector of prisons said that present conditions in jails have “no place in an advanced nation”. The Khan case threatens to illuminate how the Tory policies have made sure prison does not work, with deadly consequences for the general public. This ought to be a matter of some disquiet as there are people in custody in Britain for terrorism offences who regard prisons as “universities of terror” from which to graduate. It is not as if this problem is new. Prisons have played an instrumental role in many radical political groups including Irish republicans, German Marxists and jihadists. This history might have informed Conservative policy over the last decade so that the management of terror offenders mitigated the risks of prison radicalisation. However, the opposite appears to have happened.

During Khan’s time behind bars, the prison and probation services saw budget cuts of about 40%. Khan was in a prison service where assaults on staff and prisoners are rising. It is no surprise that prisoner violence and self-harm have become more prevalent, given that there are 2,300 fewer prison officers than in 2010 – and 378 fewer in high-security jails. With a prison system in crisis, is it any surprise that there was little capacity to deal with jihadi sympathisers among the inmates? High-security prisons were warned that extremists were able to have an “adverse influence” on fellow prisoners. The response by the then justice secretary, Michael Gove, was to have a system of “jails within jails” to prevent extremists from radicalising vulnerable prisoners. Yet this was judged to have been a failure – a verdict that should also be applied to the government’s deradicalisation programmes.

Last year the Guardian revealed the country faced a surge in the number of convicted terrorists released from prison. This when the probation service was brought to its knees by a disastrous ideologically driven attempt to manage the rehabilitation of low-and medium-risk offenders for shareholder profit. Khan, as a dangerous extremist, was overseen by the state arm of the probation service – where officers are stretched to breaking point, with workloads of up to 160% of their capacity. There have been seven Tory justice secretaries, but none has understood that their misguided policies have rent apart this country – or that austerity has bred the isolating conditions that have produced violent jihadists. About 80% of would-be terrorists are home-grown. As Neil Basu, Britain’s most senior counter-terrorism officer, noted, what the country would benefit from are “policies that go towards more social inclusion, more social mobility and more education [that] are much more likely to drive down violence … than all the policing and state security apparatus put together”. These are wise words, but unfortunately for the country Mr Johnson won’t listen to them: he’s gone fully fact-free to win this election.