The tragic death of a boat full of desperate people trying to reach the UK has focused attention on the growing numbers of people crossing the channel in small boats. This has been a problem for months now, and the Governments response has centred on implausible get tough schemes that grab the headlines but which achieve nothing; floating walls, wave machines and imaginary camps in Albania.

Any solution to the problem starts with working out who these illegal immigrants are, and why they are coming to the UK at great risk. I am going to work with relatively crude numbers, mostly because precise numbers are almost impossible to calculate. I am also dealing with historic date going back pre-Covid.

There are roughly 450,000 illegal immigrants in the UK. This doesn’t include children born in the UK to people here illegally.

The majority of these illegal immigrants – roughly 300,000 at any one time – entered the UK legally. They came over on time limited tourist visas and either overstayed their welcome or took work without the correct papers. Some came over legally but become illegal due to changes in the law.

The most common countries of origin for these illegal immigrants are Australia, Canada, the US, New Zealand and South Africa. India and China aren’t far behind. At the same time there are similar numbers Brits in those countries illegally; for every Aussie on a tourist visa doing a bar job in Earls Court there is a Brit doing the same in Sydney; for every American who came over to visit family in the old country, fell in love with a local and overstayed, there is a Brit in New York with a dodgy green card; for every Punjabi auntie overstaying her Visa to attend a cousin’s wedding there is an equivalent Brit doing the same in India.

They are almost impossible to track down because they are living with family and aren’t claiming benefits or interacting with officialdom. Typically these illegal immigrants self -deport faster than officials can track them down.

The second largest group, approximately 120,000, are here as refugees and asylum seekers, who will ultimately be granted leave to remain in the UK. They enter the country illegally because for the last 10 years to UK Government has closed all legal ways for them to enter. There is a surge of arrivals among this group at the moment driven by political instability such as the return of the Taliban to Afghanistan. Benefits are unlikely to be a main factor driving this group to the UK; benefits are very low in the UK, and are much higher in France; no-one is going to risk crossing the channel for less money. They are desperate to come to the UK because they have family here who can help support them. They are parents desperate to be re-united with children, children looking for their last living relative. Making the benefit system more miserly or brutal will do nothing to deter them.

The final group, and the most concerning are the smallest, approximately 30,000. These are trafficked into the sex trade, cannabis farms or slave labour in factories and restaurants. None of these are claiming benefits of any kind for obvious reasons. The UK is an attractive destination for slavers and traffickers because enforcement is lax, and because the UK is the only country in Europe without an ID card. David Cameron’s opportunistic decision to scrap the ID card scheme gave a huge boost to modern slavers and traffickers.

So what can we do about them?

For the first and largest group not a lot. The paradox of getting tough in immigration is that every time you tighten the rules you catch more people out who entered the UK legally, and the number of illegal immigrants goes up not down. The only way to reduce this group is by making visa rules less stringent, and making it easier for people to work while over here, ideally with a reciprocal agreement with other countries.

For the second group the only option is to create a legal route to the UK for genuine refugees and asylum seekers. We could establish an immigration centre in France staffed by UK staff so that they can come to the UK without risking the crossing and paying people traffickers. This is common sense and easily done, but politically unpopular with politicians who have benefited from the current migrant panic.

The final group are the hardest to deal with. If you can create a legal route into the UK for genuine refugees and asylum seekers you free up resources to deal with criminal gangs. Introducing ID cards will have an impact too, as will increased resources for the police.

What is clear is that the kind of fist waving and posturing the Government are currently indulging in will achieve absolutely nothing.