Against the background of widespread biodiversity loss, the issue of ecological connectivity has become increasingly important in recent decades at EU level. This growing attention can be observed in particular in biodiversity strategies or certain directives, in the establishment of key programmes or in the mobilisation of various types of funds. However, there is currently no EU framework that explicitly obliges member states to address the issue or to achieve certain objectives in this field. This article first shows how ecological connectivity has gradually emerged as a spatial planning issue, in particular through national/federal and/or regional legislative developments, in different countries (Germany, Italy and France). A focus on the French context and its Green and Blue Network Policy then depicts the implementation challenges observed in spatial planning at the regional, sub-regional and local levels. The paper highlights the difficulty of establishing a standardised framework for ecological connectivity, which implies considering the complexity of wildlife in spatial planning procedures in which potentially divergent interests intersect