Gender equality is one of the core principles of the EU. This is set forth in, for example, Article 2 of the Treaty of the European Union. Equality between men and women includes equality in the labour market. However, this equality is far from having been achieved. Building on our forthcoming research for the Martens Centre, we explore in detail four factors that may explain the gender gap in labour force participation across countries. These factors are education, taxation, the provision of childcare, and cultural and historic norms. In discussing these factors, we focus on case-study countries which represent different regions and feature diverse institutional characteristics: Germany, Italy, Poland and Sweden. Through this analysis we propose four policy actions designed to place gender equality in the labour market at the heart of a growing European economy. These are (1) the promotion of better work-life balance (2) embedding equality in national tax systems (3) tacking gender stereotypes through education and (4) understanding the benefits of long term investments for long term gains in terms of equality policies. To conclude, we acknowledge that it is preferable to implement policies that are tailored towards the institutional and cultural settings in each country and to specific groups of workers. Thus it is important that gender policies should be established at the national level. Rather than seeking to expand its competencies in the areas of education, taxation or social policy, the EU should focus on setting overall objectives.