Marine environments are central to human well being, but they are also extensively threatened by our activities. The MARLISCO proposal seeks to raise societal awareness of both the problems and the potential solutions relating to a key issue threatening marine habitats worldwide; the accumulation of marine litter. A major objective of this proposal is to understand and subsequently facilitate societal engagement in order to inspire changes in attitudes and behaviour. This proposal is a Mobilisation and Mutual Learning Action Plan with the aim of providing a series of mechanisms to engage key stakeholders with an interest in, or responsibility for, some aspect of reducing the quantity of litter entering the ocean. These will include: industrial sectors; users of coastal and marine waters; the waste management and recycling sectors; Regional Sea Commissions and EU representatives; local municipalities; citizens’ groups, environmental NGOs, school children and the general public; social and natural scientists. MARLISCO recognises the need for a concerted approach to encourage co-responsibility through a joint dialogue between the many players. This will be achieved by organising activities across 15 European countries, including national debates in 12 of them, involving industry sectors, scientists and the public, a European video contest for school students, educational activities targeting the younger generation together with exhibitions to raise awareness among the wider public. MARLISCO will make use of innovative multimedia approaches to reach the widest possible audience, in the most effective manner. The proposal will develop and evaluate an approach that can be used to address the problems associated with marine litter and which can also be applied more widely to other societal challenges where there are substantial benefits to be achieved through better integration among researchers, stakeholders and society.