This article investigates the dimension and evolution of the financing of political parties. It focuses on 28 parties in the five major European countries (Germany, France, UK, Italy, Spain), analysing the parties’ budgets from 2002 to 2016. The article's assessment shows that the availability of funds increased until the beginning of the Great Recession (2008), and then decreased, mainly due to a decline in public support for parties. Diminished state generosity has led parties to look for different sources of financing: the article shows the proportion of self-funding resources in terms of membership fees and private donations that has sustained the parties’ finances. Finally the article presents a model that helps to explain the shrinking of parties’ income by including parties’ ideological alignment, electoral outcome, presence in government and share of public financing, and countries’ public spending and GDP level, to investigate the plausible causes of the reduction of parties’ income.