ABSTRACT: After the Corston Report was published in 2007 its recommendations were accepted in principle by both the Labour Government and the Conservative Opposition. In 2010 the Conservative led coalition also accepted the recommendations in principle. Additionally, in their 2017 manifestos both parties expressed the desire to only imprison offenders who commit serious offences, when other options of punishment appear to be inappropriate. Despite their stated policy objectives, imprisonment levels have not fallen significantly since the publication of the Corston Report. They have only fallen by around 10%, to roughly 3800 female prisoners. In this thesis I analyse the policymaking process to establish how it affected policy decisions, and the achievement of policy objectives on imprisonment, particularly in relation to lowering imprisonment levels. This was done using the example of female offenders, although many of the findings apply to other groups of offenders. It was found that the policy drivers that affect policy decisions and the achievement of policy objectives concerning imprisonment were Public Opinion, Resource Management/Austerity, and the Independence of Sentencers and Punishment through the use of imprisonment. Additionally, other factors such as the values and characteristics of ministers within the Ministry of Justice and the cabinet, and the relationship and influence professionals and voluntary services, such as womenâs centres, have on sentencers can also affect the implementation of polices and affect the achievement of policy objectives. The predominance of the policy drivers above and the ideological values and characteristics of government ministers result in offenders who do not commit serious offences being managed in the community or prison, rather than being rehabilitated.