The growing awareness of functional linkages between rural and urban territories has led to a re-thinking of the rural-urban dichotomy. This was flanked by a more general reconceptualization of space, directly coming from the rise of spatial planning and the shifting process from government to governance. Thus, the concept of “soft space” came to the fore, defined as the space of governance and integrated approach. The EU Commission has launched a new instrument aimed at fostering the territorial approach of the new Cohesion Policy, namely the Integrated Territorial Investment (ITI). This research wants to investigate the added value of the ITI instrument in governing and institutionalizing the rural-urban linkages at the metropolitan level. In doing so, the author has created a conceptual framework based on three main concepts directly coming from the concept of soft space, namely institutionalization, governance capacity, and integrated approach. The empirical study is focused on Poland, in particular, dealing with the case of Warsaw, Krakow, and Wroclaw. As a result, this research argues that the ITI in Poland has represented an attempt to improve the cooperation between capital cities and their surrounding areas, even though its outcomes can be questionable.