Last Tuesday, many on the French left breathed a huge sigh of relief. After weeks of talks, the Socialists and the Greens struck a deal that will secure François Hollande the support of the Greens in the second round of the presidential elections next year, while guaranteeing Cécile Duflot’s party 15 seats in the National Assembly.

Predictably, the negotiations were an arduous and drawn-out affair: the political divide separating parties must always be navigated with care. But what is noteworthy about an otherwise banal example of political manoeuvring is the way in which the alliance has positioned nuclear energy as a key political issue ahead of next year’s contest. Of course, the crisis that unfolded at Fukushima earlier this year had already placed the nuclear industry under the spotlight for all the wrong reasons. However, the debate between the Socialists and the Greens has shown that nuclear energy is the source of deep disagreement on the left in France.

Within the Left Front coalition, for example, Jean-Luc Mélenchon’s support for a withdrawal from nuclear does not reflect the view of many members of his party. So to avoid conflict, Mélenchon has attempted to pass the buck, calling for a referendum to be held on the issue next year rather than championing his own position. For the Greens, nuclear power is at the heart of an existential debate, torn as they are between a need for representation on the national stage and their anti-nuclear convictions. Indeed for some time the party’s convictions appeared to put a pact with the Socialists beyond reach: despite the Socialists proposing to reduce France’s reliance on nuclear energy by 30 per cent over the next two decades, the Greens still held out for a promise that work on the next-generation European Pressurized Reactor (EPR) reactor at Flamanville would be halted.

The stance of the Socialists is also complicated. The recent negotiations have portrayed the Socialists as staunchly pro-nuclear when in reality, the picture is more skewed. For while the Socialists are now defending the EPR project and appear reluctant to venture too far into anti-nuclear territory, it was only in 2004 that the party condemned the ‘absurd and hasty’ decision to build an EPR at Flamanville.

This position becomes more opaque when we consider that despite his position as party leader in 2004, which implicitly linked him to the party’s official stance, Hollande himself consistently refused to be drawn on the subject. To date his position has remained largely ambiguous; while hinting that he is against a withdrawal from nuclear, Hollande claims that the Socialists will examine the matter thoroughly once they are in power.

So why is the nuclear question so divisive? Why does this issue pose such problems for the left? And why is Hollande so reluctant to take an anti-nuclear stance? The answer lies in France’s long and prosperous relationship with the atom. In the 1970s, France imported much of its electricity. Today, the country is the world’s largest net electricity exporter. Furthermore, the nuclear industry caters for over 80% of France’s domestic electricity needs. In this context, the real question is whether a gradual move away from nuclear energy is feasible, or even desirable.

A report published by the Union Française de l’Electricité last week claimed that cutting France’s reliance on nuclear energy to 50 per cent would cost the country approximately 60 billion euros. A significant amount in the current economic climate. Moreover, work on the reactor at Flamanville is now in its fourth year and has already consumed a fair share of the project’s 6 billion euro budget. And with the decline in oil resources promising a challenging energy future, nuclear seems to be a sensible investment.

Closely linked to the economic aspect is the symbolic role played by the civil nuclear industry in France. This is a more nuanced and subtle issue that draws on matters of national prestige and identity. For many years now, French companies such as Areva and EDF have been recognized as world leaders in the nuclear sector. Esteemed internationally and a source of pride at home, these ‘national champions’ showcase French engineering talent to the world.

The reactor at Flamanville is a perfect example of this homegrown talent: the first of France’s new fleet of reactors, the third-generation EPR is at the cutting edge of nuclear technology – safer and more efficient, Areva claims the reactor can withstand severe earthquakes. One of four such projects in the world, the Flamanville EPR reflects the role of France as a world-leader in not just the nuclear industry, but the broader international energy sector. On a more practical level, it is hoped that the success of the Flamanville project will provoke a wave of exports as other countries seek to acquire the new technology. Not to mention the fact that, Areva (of which the French government is majority shareholder), simply has too much to lose if the project fails.

It is these factors and more that François Hollande had in mind last week when he said that he was committed to supporting the EPR project. And also when a clause calling for a withdrawal from mixed oxide (MOX) fuel production was quietly dropped from the final text of the agreement with the Greens – Areva is, after all, the world’s leading producer of MOX. Hollande, and the wider left, know that a complete withdrawal from nuclear is almost inconceivable. The difficulty lies in reconciling this reality with their political and even ideological outlook.

Ultimately, the division on the left caused by the nuclear issue reflects how deeply embedded the industry is in France. Nuclear is part of French culture and represents one of the few areas where France can still claim to be a world leader. And although the French public has lost its appetite for nuclear since the disaster at Fukushima - a highly publicised poll published in June found that over 60 per cent of the public favoured a gradual withdrawal from nuclear – France is not yet ready to call time on its love affair with the atom.