The French political system tends to produce strong governments backed by stable majorities in parliament. Despite this, even governments with a large parliamentary majority have been reluctant to reform the pension system. This article argues that the degree of difficulty in passing pension legislation depends on the mobilization capacity of trade unions and on the timing of the electoral cycle. First, this article tries to demonstrate how trade unions matter in France and under what conditions they might cause governments to abstain from making welfare cuts. Second, it is argued that focusing solely on the veto power of trade unions appears implausible, since during the 2003 pension reform process the government ignored union protests. Hence it is further argued that a further critical variable needs to be investigated – the timing of the electoral cycle. It is therefore anticipated that governments will be more successful in passing legislation that implements unpopular reforms in the first two and a half years of a legislative period.