Countries that have adopted an "Australian-style" immigration system have higher levels of immigration than the UK, official figures suggest.
'Brexit' campaigners Boris Johnson and Michael Gove today outlined plans to introduce a points-based immigration system if the UK votes to leave the European Union on June 23.
Ending the automatic right of EU citizens to come to live and work in the UK, the policy would mean those let in would be determined by skills and qualifications and “without discrimination on the ground of nationality”.
The Vote Leave campaign plan is a response to fears over uncontrolled immigration from being an EU member. Net migration to the UK is annually above 333,000, which critics say is unsustainable - though 196,000 is due to non-EU citizens.
But official United Nations figures show immigration per head is higher than the UK in Australia, the United States and Canada - countries that already follow a points-based regime.
In 2015, 13.2% off the UK population was from "international migrant stock". By contrast, the proportion was 28.6% in Australia, 22.6% in Canada and 14.7% in the US - all higher than the UK.
Damian Green, Conservative MP for Ashford, told HuffPost UK: “It is disappointing that Vote Leave are aping UKIP’s favourite migration policy – even more so when the evidence shows it doesn’t even work.
“Vote Leave want Britain to pull out of the Single Market, costing jobs and leaving families worse off – all to try and bring down immigration. Yet their proposed system could cause immigration to rise, not fall.
“British people rightly expect a fair immigration system. Leaving Europe will not deliver that, and will be a leap in the dark that we cannot afford.”
Caroline Lucas, Green MP for Brighton Pavilion, said: “Vote Leave are all over the place on immigration.
"They say to some communities that they want more immigrants to come to Britain but simultaneously copy UKIP’s nasty Trump-style politics of division.
“EU migrants make a huge contribution to our society, with over 250,000 working in our vital public services. It’s a disgrace that Vote Leave are using them as political footballs.
“Britain is fairer, safer and greener in Europe. Following Vote Leave’s dangerous and divisive policies would be a risk we cannot afford to take."
Two years ago, Johnson said: "Why shouldn't we have some sort of points-based system, such as they have in America or Australia, why shouldn't we have that?”
The UK already has a points system for migrants outside the EU, broken down in to four "tiers" ranging from "high-value" workers to those here temporarily.
But for citizens of EU states, barring temporary restrictions for some new member states, migrants have freedom to work in the UK.
The anti-immigration Migration Watch has said the points-based regime is “totally unsuitable” for the UK, arguing it is trying to increase its population through "growth by immigration".
The Civitas think thank, cited by Vote Leave, has said that the Australian-system could lead to more EU migrants coming in to the UK than now, since it would permit plumbers, electricians and builders.
“What (Australian points based system) would not do is reduce the kinds of migration that many voters seem concerned with," wrote author Jonathan Lindsell.
"The points based system ‘skilled occupations list’ includes not only surgeons and engineers (whom we already let in) but plumbers, electricians, builders. Many EU/EEA applicants would, then, still qualify."
Under the Australian system, migrants are only granted skilled migration visas if they pass a points test based on what type of job they do, their age, English language skills, previous employment and education.
A statement from Johnson, Gove, Priti Patel, and Gisela Stuart said today: “By the next general election, we will create a genuine Australian-style points-based immigration system.
“The automatic right of all EU citizens to come to live and work in the UK will end, as will EU control over vital aspects of our social security system.
“EU citizens will be subject to legislation made by those we elect in Westminster, not in Brussels. We could then create fairness between EU citizens and others, including those from Commonwealth countries.”