The pace to achieving a sustainable plastics economy remains noticeably slow. This could be due to a lack of understanding of the role and importance of stakeholder dynamics in the plastic packaging system. Therefore, this study aims to unpack and assess the role of stakeholders in improving the plastics recycling rate and circularity in the UK, using polyethylene terephthalate (PET) drinks bottles value chain as a case study. Via the theoretical lens of stakeholder theory the study identifies and groups the stakeholders in the PET drinks bottles value chain, and tries to make sense of, and analyse, their complex interactions via the use of the Complex Value Optimisation for Resource Recovery (CVORR) systems thinking approach. This integrated approach reveals, that even though external stakeholders (e.g. NGOs, trade associations) engage with internal stakeholders (e.g. suppliers, consumers, investors), and vice versa, at different levels and scales in promoting the circularity in the PET drink bottles value chain, there is a strong drive in incentivising the production and consumption processes. This is driven by the significant lobbying power of internal stakeholders operating upstream of the PET bottles value chain (i.e. producers and brand owners), that is supported by financial institutions, and which, strongly influences national and local government policies and decision-making processes. Meanwhile, the waste management processes are short-sighted, being unable to gain improved momentum and increase the PET bottles recycling rates. This dynamic conceals, and somewhat retains, the prevailing resistance in removing the infrastructural, regulatory and technological lock-ins. A collaboration between internal and external stakeholders is paramount to sustainably managing PET drinks bottles in the UK and achieving a transition to a sustainable circular plastics economy. Creating a level playing field and fostering a closer collaboration between all stakeholders involved in the system can aid the development of new value networks, and support new policy interventions that can improve circularity in the plastic packaging sector.