There is an unmarked warehouse outside Hull station that should be a museum. It is where hundreds of thousands, possibly millions, of Jews fleeing eastern Europe’s pogroms at the end of the 19th century were isolated before crossing to Liverpool for ships to America. There is nothing new in the squalor of migration. It is about desperate people, and increasingly desperate politicians. Britain’s latest immigration obsession is about both. For politicians, the root of the desperation is an electoral lie, that Brexit would enable the government to “take back control” and slash numbers coming in. This week in a parody of such control, the home secretary, Suella Braverman, reportedly wants to deport “illegal” migrants not just to Rwanda but to Peru, Belize, Paraguay and anywhere she can land a plane. She has already donated £120m to Rwanda in return for taking 400 refugees, not one of whom she has yet sent. It is wildly extravagant gesture politics. The statistics are glaring. Immigration into Britain has not fallen since Brexit but risen. According to the ONS, the number of EU citizens who have departed has indeed declined by a net 94,000, but non-EU legal arrivals rose in 2020 by up to 303,000. The Home Office’s work and study visas issued in 2021 were up 36% on pre-Covid levels and now stand at over a million, the biggest number on record. Thus while white Europeans have been declining, the number of incomers from Asia and Africa has increased. Is that what the leave lobby promised voters in 2016? Britain needs immigrants. It needs high skills to sustain its health, science and technology industries, however cruel the theft of India’s trained doctors and Nigeria’s nurses. It needs other skills for care homes, hospitality and construction. When he was London mayor, Boris Johnson wanted more of everyone. As Brexit prime minister, he U-turned and told labour-starved employers that lower immigration would mean higher skilled and higher-paid workers. His successor, Liz Truss, to her credit, disagreed. Knowing that immigration was crucial to economic growth, she demanded Suella Braverman, then her home secretary, admit more migrants, not fewer. These posturings have had little effect on reality at the border. Britain under Theresa May was supposedly a “hostile environment” for newcomers from outside the EU. First-time refugee asylum applications are mostly in Germany, France and Italy, which took in many of the Syrian, Iraqi and Libyan diasporas. The number of homeless refugees on the streets of Trieste is now 6,500. Dealing with these seemingly unstoppable surges is an administrative as much as humanitarian issue. Compulsory deportation has long been standard across Europe for “economic” migrants. In 2004, the Home Office deported 21,425 people; in the year to September 2021, just 2,380 people were forcibly returned to another country. The reason is Whitehall chaos. The vetting system has all but collapsed. Afghans and Iranians, doctors and care workers, builders and plumbers must sit for an average of 450 days in Kent holding centres or Bloomsbury hotels – for which taxpayers are paying up to £150 a day – only for an exhausted Home Office to tell 72% of them they can stay. Were this department a hospital or local council, it would be put in “special measures”. This makes all the more absurd the tragic antics in the Channel. Even if a probable 25,000 people made the perilous trip this year, this would be a tiny percentage of the number of work visas granted. The trouble is that sea crossings are visible – and politically potent for cynical politicians. It’s easier to call landings on beaches and wanderings through Kent villages “invasions” than crowds in Heathrow’s Terminal 3. The ironies are thus glaring. A growth-oriented Britain needs new workers. It has shut out Europeans, but sheer force of demand is attracting others from the outside world, a world bursting with supply. A responsible politician should welcome these people, while guarding the British public from the appearance that public services will suffer as a result. As it is we have a home secretary ready to capitalise on the publicity along the Kent coast rather than calm the rhetoric and sort out her department. Aversion to immigration reflects the xenophobia that lurks behind much of Britain’s new identity politics. It must not be exaggerated. Research suggests that this aversion is not deep-seated. In his Substack survey, the academic Matthew Goodwin pointed to a recent welcome for Afghans, Hongkongers and Ukrainians. Ipsos-Mori notes a buyer’s remorse among leave voters. Those ready to see immigration rise have tripled since Brexit, from 9% to 31%, while those wanting less have fallen from 81% to 64%. There is an opportunity here for sanity. The Home Office would save itself money and trouble by giving every applicant to its Paris consulate a temporary work visa on the spot. The Strait of Dover would empty. Simon Jenkins is a Guardian columnist