This paper presents results from a study of future bioenergy use in Europe, within the specific context of an enlarged EU, including agricultural reforms suggesting opportunities for large scale production of biomass for energy in Central and Eastern European countries, and given different climate change related policies. The analysis is made using a cost-minimization country-level energy and transport system model for Europe. The domestic biomass potential seems sufficient to meet the proposed demand for biofuels for transport in Europe to 2030. But competition for available bioenergy resources is likely to arise. Under a stringent carbon cap regime, biomass demand in stationary applications is the major driver behind the bioenergy expansion. Transport biofuel policies may redirect biomass flows from stationary uses to the production of transport fuels. Thus, ambitious biofuel targets in EU-s transport sector can reduce the efficiency of biomass use for CO2 emission reductions. However, it may still be justifiable to use biomass for transport today, e.g., if a lack of technological progress for other carbon neutral transport fuels, e.g., hydrogen, lead to that biofuels will be required for reaching ambitious long term CO2 targets for the transport sector.