I’ll start by declaring an interest. Yesterday I had my hair cut in at a barber’s set up and staffed entirely by immigrant workers. I then passed two street cleaners talking to each other in Polish on my way to a coffee shop where the barista serving me was Romanian. Picking up my coffee I boarded a bus driven by a man with a Caribbean accent on my way to hospital where I had an operation that was, admittedly, performed by an English surgeon, for which I was referred by an English GP. But every single other person who dealt with me at the hospital, from my pre-assessment check up to checking me in to nursing me before and after the operation, to the porters who wheeled me along to the anaesthetist who rather expertly knocked me out for an hour until I woke up feeling really rather chipper in the recovery room where a Ghanain man looked after me, were ALL immigrants to this country.

The questions I have today are two simple ones: How many of these people above are vital to us having a vibrant Economy? But how many of those people above would have got into the country if we had an “Australian-style” points system for entry?

In Australia, points are awarded for skills, experience, medical checks and character checks. Communities are consulted, economic models tested and annual numbers are capped. It is superficially attractive, as Boris Johnson and Michael Gove pointed out, because it allows the UK to welcome new citizens who wish to contribute to society while “leaving us able to remove those who wish to abuse our hospitality”.

Yet Migration Watch, who are a pressure group campaigning for lower immigration, has dismissed the model as “thoroughly unsuitable” for the UK. In fact, we have tried the system here in 2008 for non-EU migrants and it proved inadequate. Points were awarded for qualifications, language skills and the existence of a firm job offer. But it eliminated human discretion and took no account of the fact that skills can be acquired, languages learned, jobs found, and that immigrants, by definition tend to be self-starters, more likely to start businesses for instance.

What’s more, half of migration into this country comes from outside the EU, which would be unaffected by Brexit. Of the 270,000 EU migrants who came to the UK last year, almost 200,000 came with a job offer and in 2014 paid £3.1 n in tax, five times more than they received in benefits.

Let’s put this more starkly with the help of a study by Oxford University’s Migration Observatory, which found that if the points system we used in 2008 were applied to EU migrants, over three quarters of them would fail. “Good” you might say. But is it practical or even desirable to impose such tests on a 25 year-old who wants to be a barista in a coffe shop, a Bulgarian who wants to pick asparagus or a young Greek escaping high unemployment in his country who is happy to do jobs that many Britons scorn?

Then there are the concerns, often aired by Brexiters, about welfare and health tourism. This ignores facts, which are that around 40,000 EU migrants claim any benefits at all, accounting for only 2.5% of the benefits administered by the Department of for Work and Pensions on 2014.

As for health, yes, money must be made available for the recruitment of more doctors and nurses, and planning restrictions on housing development need to be eased. But only 10% of our country is actually built upon. Land use is inefficient and population distribution is poor. Building more new towns within commuting distance of cities like Glasgow and Manchester would help to ease the pressure on the South East.

A friend of mine runs a large national recruitment agency. His database has 750,000 (yes, seven hundred and fifty THOUSAND) job vacancies on it, spread around the country. This vacancies will mostly be filled by migrants. This is because, he said to me off the record, too many Brits only want to do jobs with wages a firm can’t afford, within walking distance of their home, and with job conditions that would make it hard to know the difference between work and a holiday.

The free flow of labour is vital to the success of the British economy. This idea that we can ‘control’ immigration will only work if it is flexible and nuanced, and achieving that is almost impossible. If Brexit means raising the drawbridge, then count me out.