Glyphosate is a widely used herbicide across a wide range of UK crops and in the amenity and home and garden sectors as it is a broad spectrum, systemic herbicide that provides a wide range of benefits to users. Glyphosate is strongly adsorbed to soil particles and, even though it is highly water soluble, it does not leach readily into soil and ground water. Monitoring studies show that glyphosate findings in groundwater are rare (typically <1% of the samples). Glyphosate is however frequently detected in surface waters (20–30% of the samples), but generally well below the threshold for ecotoxicological concern. Nevertheless, the presence of glyphosate in water at all has led to concerns that restrictions may eventually be put on its use. To place this in context, this paper assesses the value of glyphosate use, both pre-harvest and post-harvest/preplanting, in the main UK arable crops (cereals and oilseeds) and looks at the potential implications of a withdrawal of approval for the use of glyphosate on combinable crops in the UK.