For the first time in more than 30 years, a new French political force – not only to the left of the Socialists, but also unafraid to assert itself as an alternative to them – scored double figures in a presidential election: 11.1%, climbing to 16% in large cities. This achievement of the Front de Gauche (Left Front) represents the most recent and the strongest success of the "other left" in Europe.

After too many years of fragmentation, the Front de Gauche has managed to unify the leftist forces that advocate social and environmental transformation. Now we must make sure that Nicolas Sarkozy is ousted from the Elysée with a crushing defeat in the second round of the presidential election on 6 May. The French people and the labour movement will have a lot to lose if the radicalised right – which, moreover, is after the extreme right's votes – monopolises state power. This is our first and most urgent mission.

But this short-term objective should not be confused in any way with support for the Socialist party's candidate or his programme. François Hollande's policies are designed, with some exceptions, to meet the requirements of financial markets and the "golden" balanced budget rule of the European fiscal pact – which he refuses to put to a popular referendum.

The Left Front, created in 2009, has in its first presidential election mobilised close to four million people. This is nearly three million more than at the previous two national elections – the European ones in 2009 and the regional ones in 2010 – at which the party had fielded candidates. Throughout these elections, our agenda has been clear. We reject austerity in France and Europe in all its forms (whether these are the "hard" measures of the conservative right, or the "soft" ones of social democracy); we reject the existing neoliberal treaties of the EU; we demand a new distribution of wealth in favour of the workers and those in insecure employment; and we want public services that differ from those of a marketised society. We want to use ecological planning to get out of the capitalist crisis; a greater public involvement in state affairs to counter our oligarchic democracy; and an exit plan from Nato and the Atlanticist strictures imposed on our country.

The Front de Gauche will also be a people's front – and will fight tirelessly against the far-right Front Nationale whose increase in popularity is, of course, worrying. We were right to target them, analysing and challenging ing their proposals throughout our campaign. We were the only ones to do so – without our focus, perhaps the results would have been even more alarming.

But what is clear is that the time for a resistance to financial markets has now come. It was amusing to observe this week some prominent representatives of the financial oligarchy – Mario Monti, Italy's prime minister, and Mario Draghi, the president of the European Central Bank, for example – vindicating our analysis of the dangers of austerity policies. They lead European economies into a recession that carries with it, as clouds carry storms, unemployment and poverty for the peoples of Europe. According to Draghi, it would even be proper to rewind and complete the "fiscal pact" with a "growth pact". This matches the views of both Monti and Hollande. But what kind of growth would it be? One that promotes the flexibility of labour markets as engines of "competitiveness" of the European economies?

The Front de Gauche offers a different conception of the economy, of society and of the EU. In this context, we have another compelling reason to dislodge Sarkozy from his presidential seat. By getting rid of him, we will break the "austeritarian" axis symbolised by the Merkel-Sarkozy relationship. This would finally allow us to go forward and build a new balance of power in Europe – one that truly challenges the politics of austerity.

In this battle the Front de Gauche holds, in France, the keys to the future.

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• This article was translated by Jessica Reed