This paper summarises the findings of work package 5.3 of the SECURE project, with regard to the role of carbon capture, transport and storage (CCTS) for the future European supply security of coal. The real issue in European supply security with respect to coal is the absence of an economically and politically sustainable use of coal for electricity, liquefaction, gasification, etc. Whereas earlier papers delivered for work package 5.3 on the coal sector indicated that there are few risks to the European energy supply of (steam) coal, there is an implicit supply security threat, i.e. that coal will no longer be an essential element of European energy supply because the CCTS rollout will be delayed or not be carried out at all. This thesis is substantiated in this subsequent paper, with more technical details and some case study evidence.This Working Document is a follow-up to the SECURE project, financed by the European Commission to study the "Security of Energy Considering its Uncertainties, Risks and Economic Implications". The CEPS Working Documents are intended to give an indication of work being conducted within CEPS research programmes and to stimulate reactions from other experts in the field. Unless otherwise indicated, the views expressed are attributable only to the authors in a personal capacity and not to any institution with which they are associated.