The rise in e-commerce has increased last mile parcel deliveries, in turn affecting the sustainability of transport. With the worldwide efforts to minimise fossil fuel use including the UK Government's plans to end the sales of new petrol and diesel vehicles by 2035, alternative fuels need to be explored. Currently, one of the most promising solutions is the electric vehicle (EV) which produces zero tailpipe emissions. This paper aims to explore the challenges of adopting EVs in final mile parcel deliveries, and thus identify potential directions for future research. To achieve this, we developed a systematic literature review to understand the nature of these challenges better and provide a background from which to acquire more information from leading logistics companies in the form of in-depth interviews. We found that the companies encountered different challenges based on their fleet sizes, schedule and capacity to implement the required structural and infrastructural changes to support the efficient running of their last mile delivery operations on EVs.