Transport is Europe’s biggest climate problem, representing 27% of the bloc’s greenhouse gas emissions. If Europe is to meet its climate targets and avoid the severe impacts of climate change, additional action is needed to tackle emissions from the transport sector. Meanwhile, the EU is drafting the post-2020 budget with a proposal expected in May 2018. The annual €10-14 billion gap that will be left as a result of the UK’s departure from the EU has triggered debate on alternative sources of revenue for the EU budget. This position paper outlines how a green tax shift has a key role to play in tackling transport emissions and addressing a gap in the EU's budget post-2020.