 Hello, my name is Catherine Barnard. I'm Professor of European Union Law here at the University of Cambridge and I'm also a senior fellow in the UK in a changing Europe programme. I'm here to talk about free movement of workers. Free movement of workers is one of the so-called four freedoms together with free movement of goods, free movement of services and free movement of capital and these form the core of the so-called single market which a lot of British people thought is what we signed up to back in 1973 when we joined the European Union. Now free movement of workers is really important. About two million EU migrant workers are working in the UK and they're doing a range of jobs from collecting vegetables in the fields to high-skill, high-level jobs in the NHS. You probably will have encountered a poll or a lapbion when you go into any of the big coffee shops. These are people exercising their rights under what's called Article 45 of the Treaty. But it works both ways. British people are working in other member states in France, Germany, Spain and they are relying on exactly the same rights that Polish people are when they're coming to the UK. So what are the strengths and the weaknesses of free movement of persons? Well the good things are we are getting a large number of migrants here to do jobs that otherwise are not being filled in the UK. They're bringing their skills and their education with them and they're contributing to our economy and in fact they contribute more than they take out. The negative side is that of course they are taking jobs that would otherwise possibly be done by nationals although that view is contested by economists. They are perhaps creating pressure on wages particularly at the low end there's some evidence that perhaps wage suppression is of the order of about 1% and they are claiming benefits particularly in work benefits because they are doing a lot of low skill jobs but also some out of work benefits albeit that they're claiming less out of work benefits than the native population. So what effect will there be if the UK votes to leave on the 23rd of June? The answer is nobody really knows because it much depends on what is put in place of EU membership. If we do a Norway which is shorthand for joining the European economic area then free movement of persons will continue in much the same way as we know it at the moment. But Boris Johnson and Michael Gove both said that that's not what they want the UK to do they rather envisage a free trade agreement a bit like the one that the EU currently has with Canada. Now if it's a free trade agreement that's about goods and therefore there will not be the right of free movement of workers and therefore free movement of workers will be covered purely by domestic immigration rules. And so that will clearly have an impact on the numbers of migrants coming into the UK from the European Union because a points based system will be applied to them which will disadvantage those who have low skills. What do we think going forward? The reality is that migration will continue and even at the moment there is more non-EU migration in the UK than there is EU migration so there are more people coming from non-EU member states about 270,000 than there are EU migrants coming to the UK and as far as non-EU migrants are concerned the UK does have control over those numbers. Nevertheless it's thought likely that whatever form the post Brexit world looks like there will continue to be migration but it does raise issues for EU migrants currently working here and also for British migrants working in other member states.