The first round of the French presidential election is five months away, yet France is already in political turmoil. There are several reasons. First, François Hollande, the incumbent president, is so weak and discredited that some expect him to pull out of the race altogether. This would be an unprecedented move for a president in office.

Second, Marine Le Pen, leader of the Front National, is going from strength to strength. She is consistently polling at more than 20% of the share of the vote (against 17.9% in 2012) and seems guaranteed to make it to the second and decisive round of next year’s presidential elections. What’s more, Le Pen’s rise has been directly affecting her opponents across the political spectrum.

Rather than pushing back against her ideas, mainstream politicians have opted to emulate some of her key policy proposals. This is not a question of a left and right divide. Most high-profile politicians of all stripes have embraced Le Pen’s agenda: they promise tough law-and-order solutions; they constantly talk about “national identity”; they defend “republican values under the threat of Islam”; and they promote an exclusive if not discriminatory brand of secularism (laïcité). Last but not least, they insist that immigration, the FN’s pet topic since the 1980s, has to be curbed.

Anti-racist associations apart, the French public has shown little support in general for economic and political migrants. There have been situations of tension, in Calais notably, between migrants and the local population. In an October 2015 poll, 67% of the French population declared that family and housing state subsidies should only apply to EU migrants and 61% would like the government to scrap medical assistance for illegal migrants.

A September 2016 poll showed that 62% opposed welcoming in Europe migrants and refugees who sail to the Italian or Greek coasts. Notably, the level of support for migrants has decreased across voters of all political inclinations

The key question to ask on immigration, especially in the light of the Brexit vote, is: are there signs of the aversion to non-European migrants and lack of support for refugees extending to EU migrants?

Unlike in Britain the French population has not tended to direct its anger at EU workers. There could be a practical explanation. Tony Blair’s government enthusiastically opened up Britain’s borders to eastern European workers from 2004, the year of accession of 10 new member states. France, instead, restricted dramatically the conditions of access to its internal markets. Since then, the French government has fully adopted EU legislation, although it has never “caught up” with Britain on the number of eastern European migrants who work and live there.

A majority of French and British voters share the same dislike for EU bureaucracy, its byzantine legislation and the feeling of loss of “sovereignty”, which has to be “regained”. In France, there are also similar issues of racism and xenophobia, but these tend to focus on French citizens of foreign descent, notably from former colonies in North Africa.

So, for the moment, no mainstream politicians in France challenges the principle of free movement in the EU. Discussing Brexit in the British press recently, Nicolas Sarkozy warned Theresa May that no European government could agree to grant the United Kingdom free access to the single market if Britain does not accept free movement.

For a majority of French politicians, immigration is a problem, but it is essentially an extra-communitarian one. Manuel Valls, the prime minister, stressed the importance for Europe “to take urgent action to control its external borders… otherwise our societies will be totally destabilised”.

Former French president Nicolas Sarkozy delivers a speech during an election campaign rally in Nimes last week. Photograph: Guillaume Horcajuelo/EPA

Despite a steady increase in Euroscepticism in France, the underlying principle of free movement of people across the EU remains broadly undisputed. Apart from in one telling area. There is growing evidence of opposition towards EU migrants and the notion of freedom in what has become known as “social dumping”. This relates to “posted workers”, employees sent by their employer to carry out a service in another EU member state on a temporary basis. Those EU workers do not integrate in the labour market in which they work.

Hence, “social dumping”, where foreign service providers undercut local service providers because their labour standards are lower (in terms of pay and social protection). Interestingly, the most staggering attack against posted workers has come not from the far right, as one would expect, but from the radical left.

Jean-Luc Mélenchon, an MEP, a presidential candidate in 2012 and running again in 2017, has singled out posted workers in a speech at the European parliament last July. He declared that “posted workers took the bread out of French workers’ mouths”. Part of the French left was stunned by words that could have easily been uttered by Marine Le Pen.

It is undeniable that economic migration in France and in the UK has been, in some circumstances, poorly planned and has put a strain on public service provisions (schools, nurseries, hospitals). But still the prevailing view in France would be that EU migrants themselves are not responsible for the situation.

Our governments, it follows, have let people down by underinvesting in public services, by decisions they have taken in the first place: in 2004, the decision to enlarge Europe and the dismantling of the welfare state.

Economic migrants have become a convenient scapegoat, but by launching unprecedented austerity policies our governments have created a situation in which national states cannot cope with the sudden influx of EU workers at times of economic recession.

Sarkozy and Le Pen aim to take away immigrants’ rights and social protection that might not even be reallocated to nationals because of further spending cuts. But, at least for the moment, they don’t have EU migrants in their sights.