Immigration, in particular the free movement of European Union nationals into Britain to work, is widely acknowledged to have been one of the major drivers of support for the Leave vote in June's referendum.

And the Prime Minister Theresa May has since made controlling EU immigration flows one of her principal objectives for her Brexit negotiations with the rest of the Continent.

Yet immigration is an area plagued by emotive arguments, confusion and questionable assertions.

Below Jonathan Portes, the immigration expert and Research Fellow at the National Institute of Economic and Social Research, busts six of the major myths about immigration and public policy on immigration in the era of Brexit.

1. "Even if we end free movement, there’s no way we’ll ever get immigration to the tens of thousands"

Actually, over the next two years EU migration is likely to fall, for several reasons:

• Even before the referendum, employment growth in the UK had slowed (meanwhile unemployment in the rest of the EU is falling).

• Moreover, for some countries at least (in particular Romania and Bulgaria), the very high levels of recent inflows reflects the impact of the lifting of transitional controls in 2014; this seems likely to run its course. Even if there had been no referendum, immigration would probably have fallen back from its peak earlier this year.

• The referendum could make this fall much sharper. This is not just because of the overall economic impact of Brexit on growth, output and employment. A Brexit-related slowdown will hit some sectors and regions – such as the finance sector in London – that employ large numbers of EU migrants. Moreover, migration from some EU countries appears to respond to exchange rate changes, presumably because migrants compare the salaries that they could earn at home to what they can earn here.

• To these economic reasons must be added legal and psychological ones. There will be a prolonged period of uncertainty before we know exactly what Brexit means both for EU citizens here now and new arrivals. If people cannot plan with any confidence they are less likely to come and less likely to stay. Moreover, not only have we seen isolated but very unpleasant outbreaks of racism, but there is a much more widespread sense that they are no longer welcome.

Combined with likely falls in non-EU migration as well, immigration might fall faster than anyone expects.

Theresa May's Brexit strategy like a plan from Baldrick - Corbyn

2. "The government has rejected the Vote Leave option of an 'Australian-style points based system' "

It appears certain that we will move to a system where the UK government sets out some criteria (skills, occupations, salaries, numerical limits etc) for work-related migration from the European Economic Area, as it does at present for non-EEA migration.

Such a system could well be described as an ‘Australian-style’ system, since this is what Australia (like many other countries) does; it could also be described as a work permit system, since those who qualify receive permission to work here.

This debate tells us essentially nothing about what the overall system will look like post-Brexit.

In fact, there are two key choices:

• Will the new system give a considerable degree of preference to EEA citizens, even if not full free movement, compared to those outside the EEA, or will it treat all non-UK citizens equally (with the possible exception of Irish citizens)?

• Will the new system be relatively liberal, accepting perhaps an increase in skilled migration from outside the EEA at the same time as reducing EU migration? Or will it be restrictive, with the overarching objective still being to hit the government’s target to reduce net migration to the tens of thousands?

3. "Ending free movement means we’ll 'take back control' of our borders"

Immigration control (of EEA nationals) does not (mostly) mean border control.

It does not seem likely that we would restrict EEA nationals’ right to enter the UK without a visa.

A fully fledged visa regime for EEA nationals would be hugely disruptive to trade, travel and tourism - even leaving aside the obvious point that this would mean UK nationals would require visas to travel to continental Europe.

And it would mean that they were treated worse than, for example, Americans or Australians, who do not need a visa to enter the UK.

So EEA nationals (like UK nationals) already have their passports checked at entry and this will continue; equally, they are only denied entry in rare circumstances.

This means that control over how many and which EEA nationals are allowed to work in the UK will not, in practice, be applied at the border in the vast majority of cases.

As with other non-visa nationals, like Americans or Australians, it will be applied in the workplace; employers will have to verify that EEA nationals are entitled to work in the UK, just as they currently do for non-EEA nationals.

Talking about ‘border controls’ for EEA nationals or reintroducing ‘controls’ over ‘who enters the country’ misses the point almost entirely.

What experts have said about Brexit Show all 11 1 /11 What experts have said about Brexit What experts have said about Brexit Chancellor of the Exchequer Philip Hammond The Chancellor claims London can still be a world financial hub despite Brexit “One of Britain’s great strengths is the ability to offer and aggregate all of the services the global financial services industry needs” “This has not changed as a result of the EU referendum and I will do everything I can to ensure the City of London retains its position as the world’s leading international financial centre.” Reuters What experts have said about Brexit Yanis Varoufakis Greece's former finance minister compared the UK relations with the EU bloc with a well-known song by the Eagles: “You can check out any time you like, as the Hotel California song says, but you can't really leave. The proof is Theresa May has not even dared to trigger Article 50. It's like Harrison Ford going into Indiana Jones' castle and the path behind him fragmenting. You can get in, but getting out is not at all clear” Getty Images What experts have said about Brexit Michael O’Leary Ryanair boss says UK will be ‘screwed’ by EU in Brexit trade deals: “I have no faith in the politicians in London going on about how ‘the world will want to trade with us’. The world will want to screw you – that's what happens in trade talks,” he said. “They have no interest in giving the UK a deal on trade” Getty What experts have said about Brexit Tim Martin JD Wetherspoon's chairman has said claims that the UK would see serious economic consequences from a Brexit vote were "lurid" and wrong: “We were told it would be Armageddon from the OECD, from the IMF, David Cameron, the chancellor and President Obama who were predicting locusts in the fields and tidal waves in the North Sea" PA What experts have said about Brexit Mark Carney Governor of Bank of England is 'serene' about Bank of England's Brexit stance: “I am absolutely serene about the … judgments made both by the MPC and the FPC” Reuters What experts have said about Brexit Christine Lagarde IMF chief urges quick Brexit to reduce economic uncertainty: “We want to see clarity sooner rather than later because we think that a lack of clarity feeds uncertainty, which itself undermines investment appetites and decision making” Getty Images What experts have said about Brexit Inga Beale Lloyd’s chief executive says Brexit is a major issue: "Clearly the UK's referendum on its EU membership is a major issue for us to deal with and we are now focusing our attention on having in place the plans that will ensure Lloyd's continues trading across Europe” EPA What experts have said about Brexit Colm Kelleher President of US bank Morgan Stanley says City of London ‘will suffer’ as result of the EU referendum: “I do believe, and I said prior to the referendum, that the City of London will suffer as result of Brexit. The issue is how much” What experts have said about Brexit Richard Branson Virgin founder believes we've lost a THIRD of our value because of Brexit and cancelled a deal worth 3,000 jobs: We're not any worse than anybody else, but I suspect we've lost a third of our value which is dreadful for people in the workplace.' He continued: "We were about to do a very big deal, we cancelled that deal, that would have involved 3,000 jobs, and that’s happening all over the country" Getty Images What experts have said about Brexit Barack Obama US President believes Britain was wrong to vote to leave the EU: "It is absolutely true that I believed pre-Brexit vote and continue to believe post-Brexit vote that the world benefited enormously from the United Kingdom's participation in the EU. We are fully supportive of a process that is as little disruptive as possible so that people around the world can continue to benefit from economic growth" Getty Images What experts have said about Brexit Kristin Forbes American economist and an external member of the Monetary Policy Committee of the Bank of England argues that the economy had been “less stormy than many expected” following the shock referendum result: “For now…the economy is experiencing some chop, but no tsunami. The adverse winds could quickly pick up – and merit a stronger policy response. But recently they have shifted to a more favourable direction” Getty

4. "To stop EU migrants 'sneaking in through the back door' we’ll need border controls with Ireland"

It follows from 3 that this is a non sequitur.

Why would someone who plans to work illegally in the UK go via Dublin when she can simply fly to Stansted?

There will be issues relating to people coming via Ireland (third country nationals, as now, and security concerns) but we won’t be controlling migration on the Irish border.

The need for control on movements of goods (assuming we leave the Customs Union) is a much more difficult issue.

Corbyn says Brexit has been 'chaotic' and needs a more 'grown up approach'

5. "Ending free movement means we’ll be able to have 'only the [high-skilled] immigrants we want/need' "

It is often claimed that if the UK could impose restrictions on migration from the EU, the impact would be to reduce migration for unskilled and/or low paid work, while having no impact on skilled migration; possibly even allowing an increase.

This ignores the nature both of migration systems and outcomes.

No system can select perfectly, or even close to it. The view that we can devise an immigration system that allows in those, and only those ‘immigrants that have the skills we need’ is fantasy.

Moreover, it also ignores the fact that migration is not just a matter of the UK choosing migrants; migrants have to choose us.

Even if we wish to remain open to skilled migrants from elsewhere in the EU post-Brexit, they may not choose to come here (or remain here).

Almost any system will increase in bureaucracy and reduce the rights of those who come; including those of their spouses to work and study, of their children to citizenship, access to the NHS and so on.

And beyond this are the wider psychological and attitudinal consequences of Brexit.

Skilled migration will fall – maybe by a lot.

6. “Leaving the EU will enable us to reduce burdens on business – especially damaging employment rules”

The government has already said it doesn’t intend to use Brexit to make any significant reductions in the protections or rights of British workers.

But ending free movement will definitely result in a large increase in the regulatory burden on business.

This follows from 3; employers will be at the sharp end of enforcing an end to free movement of workers.

They will have to check the rights of EU citizens to work, just as they do now for non-EU citizens.

This won’t be easy – most of the 3 million already here will be given some sort of permanent residence rights, while there will be a new system for new arrivals; itself a new burden.

Almost certainly there will be a significant increase in illegal working, and the Home Office will need to devote more resources to enforcement, resulting in further burdens.

When it comes to immigration, “taking back control” means expanding the size and role of the state.