I have consistently argued that it is absolutely essential for a sovereign country to be able to choose the number, usual occupation and character of those wanting to come to the country in question. Why?
Firstly, why do we need immigrants at all? The answer is straightforward. There is never a perfect match between the needs of industry and the skills of the working population. Therefore we need to attract people from abroad able to provide the relevant know-how/ skill-sets. In addition, we need to do our humanitarian duty by providing a safe haven for a reasonable share of genuine refugees fleeing the ravages of war, natural disasters etc. However, immigration policy at any time has to strike a balance between these considerations and the impact of population increase on infrastructure and facilities such as housing, the NHS, etc. Obviously we also need to ensure that individual immigrants do not pose a threat to our security.
While we are in the EU we cannot say 'no' to anyone from another EU country. It is simply impossible to strike the balance I refer to above. If the country is doing well relative to our neighbours in the EU, the entry-demand from these countries increases significantly for obvious reasons and net immigration soars. Our infrastructure/ services are unable to cope at short notice, a crisis ensues and our wellbeing takes a dive. Additionally, we find it difficult to say 'yes' to needed skilled applicants from non-EU countries - such as computer programmers from India - because of these same pressures. It is also much more difficult to refuse entry to those coming from the EU that are not known terrorists but who, we believe, may well pose a security risk.
This issue will become much more acute as the EU continues to expand to include more countries.
I believe that it is very important for the UK to get complete control of immigration and this is why I have voted to leave the EU.