Contemporary capitalist societies suffer from a threefold democratic deficit. Important areas of life and human activity are excluded from democratic control: Most workplaces are non-democratic. Key economic decision, e.g., what to produce, how to produce and for whom to produce, are not made democratically but by the market. And democratic politics are increasingly threatened by capital mobility and financialization: Global markets curtail effective democratic sovereignty. In this paper I put forward three sets of claims. Firstly, I offer a diagnosis of the threefold democratic deficit and argue that capitalist private property rights are at its heart. Capitalist private property rights in the means of production stand against democracy at the workplace, against democratic planning of productive processes and against the implementation of democratic political decisions. Secondly, I argue that the tension between capitalist private property rights and the requirements of democracy ought to be resolved in favour of democracy. The requirements of democracy take priority over private property rights. And finally, I sketch two arguments in favour of economic democracy, combining resources of contemporary democratic theory with what I believe is a neglected tradition in the history of the labour movement.