On the morning of September 15 last year a botched ‘bucket bomb’ partially exploded on a rush-hour train at Parsons Green tube station, injuring about fifty passengers.

The perpetrator, Ahmed Hassan, who claimed to be 18, had arrived illegally in the UK in October 2015 from Iraq via Calais, using a similar route through the continent to – among others – the 2015 Paris bombers. In order to be granted asylum, Hassan lied about his age and claimed to be a minor, taking advantage of a recent decision by the UK Government to admit more unaccompanied child migrants from Europe. During an interview with immigration officials in January 2016, Hassan confessed to having been trained by ISIS. Undeterred, officialdom promptly placed him in the care of an unsuspecting elderly couple. He carried out the attack while his asylum application was being processed.

This was – to date – the most preventable terrorist attack in memory. The authorities knew Hassan had arrived from a safe country. They knew he had used a route known to be infiltrated by terrorists. They knew his first act upon setting foot in this country was to break the law by virtue of entering illegally. And once here, apart from being an ISIS associate, they could not ascertain who he was. In short, the Parsons Green bombing was a national scandal: an act of gross negligence by the state.

Hassan was jailed for life with a 34-year minimum term in March. However, there was no public inquiry into the Parsons Green bombing. In fact, there was no statement or utterance from the government at all. Granted, no one died in the attack, but that does not take away from the rank incompetence that allowed it happen. Instead, we were dished up the ‘Keep calm and carry on’ mentality.

And for a while we did. Until on Tuesday, just outside the Palace of Westminster, a Ford Fiesta swerved into pedestrians and cyclists, injuring three. The man pulled from the car at the scene

was named as 29-year-old Salih Khater, originally from Sudan. He remains in custody on suspicion of terrorist offences and attempted murder, having reportedly refused to cooperate with police.

At the time of writing, Khater’s full backstory has not been revealed. However, we know that he arrived in 2010 from Libya, a terrorist hotspot 2,000 miles from the UK. His subsequent asylum application was successful, and friends claim he acquired full British citizenship a few weeks before the Westminster incident.

At present, prospective refugees – irrespective of any transgressions, it would seem – are normally given temporary right to remain, and are not subject to any loss of liberty or monitoring while their application is evaluated. Furthermore, it is now demonstrably clear that the vetting process of applicants is, to put it mildly, not up to standard.

In future, all asylum seekers should be held in secure reception centres upon arrival. Here, cases involving those who travel through safe countries should be dismissed and the applicants deported. All other applicants should be subject to comprehensive screening before their right to remain and freedom of movement is granted. Those whose identity cannot be verified and cannot be deported should be held in comfort and dignity until further action is possible. These would be equitable, proportionate and lawful measures for our country to take.

Had Hassan not been such an inept bomb-maker, or had there been more pedestrians in Westminster on Tuesday, both acts could have resulted in dozens of deaths. I pray that is not what it takes for our Government to act.