The freedom of movement of workers (not persons per se) is one of the four pillars of the European Union and is an integral part of the EU single market. This 'entails, among others, the right for workers of the Member States to accept offers of employment anywhere within the Union.'
(See pp.12-16 for useful summary in UK/Heads of Government New Settlement that Cameron sought from and was agreed by Council of Ministers in February 2016. This became defunct when the UK EU referendum achieved a majority in favour of Brexit.)
Population Growth and Immigration
In this Eurostat table population growth in the UK is attributed more to 'positive net migration and adjustment' than to natural change. This is the case in 12 EU and EFTA Member States. (see Table 1 below). In only two EU Member States is population change attributed 'only to positive net migration' - Germany and Italy.
Freedom of movement of workers and the UK New Settlement of Feb 2016
In the UK/Heads of Government New Settlement of Feb 2016 the UK won, amongst other things, a concession on limiting the access of new EU workers in the UK to in-work benefits (such as in-work tax credits) for a period of four years on a tapered basis (seeD/2b p.15). This was termed 'an alert and safeguard mechanism'.
In Annex 5 to the New Settlement it states that 'The EC considers that the kind of information provided to it by the UK shows the type of exceptional situation that the proposed safeguard mechanism is intended to cover exists in the UK today.'
And 'accordingly the UK would be justified in triggering the mechanism in the full expectation of obtaining [EC?] approval' (New Settlement, Annex 5 p.2).
This decision seems quite important because:
a) the EC recognised on the basis of information provided to it by the UK that an 'exceptional situation' with regard to Freedom of Movement in the UK existed;
b) that this exceptional situation would have justified the UK in triggering the safety mechanism agreed in the New Settlement that would have restricted in-work benefits to newly arriving and newly employed non-UK EU workers in the UK four a four year period on a tapered basis;
c) that this restriction that applied only to non-UK newly employed workers would have constituted clear discrimination in the UK labour market which is expressly outlawed (at least a a general level) within EU legislation;
d) although Annex 5 recognises that an 'exceptional situation' exists in the UK the information provided to the Commission on which this is based was not published.
On the basis of a-c above this would seem to give the lie to those who assert that i) Freedom of Movement as it currently exists within the EU is sacrosanct, ii) that the EC and Council of Ministers will never bend on Freedom of Movement and iii) that the EC and Council has not been willing to make specific concessions to individual Member States on Freedom of Movement when that Member State can demonstrate an 'exceptional situation'.
Of course, it can be argued that that the New Settlement was made in extremis in response to the then forthcoming UK EU membership referendum. Which is true.
It can also be argued that the concession made was never actually put into practice and that the proposed amendment to Regulation 492/2011 was never actually agreed (by qualified majority voting?) by the EU28 Member States at the Council of Ministers. (The FT noted on Feb 3 2016 (p. that even high-priority EU legislation can take more than six months to be passed).
And lastly it could be argued that the change proposed was both time limited (4 years on a tapered basis) and temporary (there was no agreement on how long it would last) and did not signify that big of a change in the Freedom of Movement pillar of the Single Market.
But it did show that in extremis the EC and Council of Ministers was willing to consider and propose changes to the sacrosanct Freedom of Movement of workers. And it seems to me that at least in principle if not in scale the shift was substantial because it sanctioned discrimination in the UK part of the EU labour market in favour of UK workers.
There is the question of the workability of these restrictions on the Freedom of Movement of Workers. One UK official at the time believed that they were 'unworkable' (see FT 23 Feb 2016 front page article)