This article focuses on the role of unionised members of parliament. While unions have a direct effect on the labour market via wage negotiations, they often also take part in political debates. In many countries, significant shares of the members of parliament are also members of a trade union. However, up to now little empirical evidence is available on the extent to which unionised members of parliament try to achieve union-specific goals and thereby influence the macroeconomic conditions of an economy. A recent study for Germany comes to the conclusion that union members in the Bundestag cannot be seen as the parliamentary arm of the trade unions. However, we present contradicting empirical results by showing that, in Germany at least, the degree of unionisation of parliamentary members has a negative impact on economic growth and increases inflation, while unemployment remains unaffected.