In this thesis, I argue that human rights charters can improve protections for criminal offenders against penal populist laws that objectify and exclude them. In cases where such laws have been challenged on separation of powers or other grounds in Australia, the Courts have frequently used highly formalistic and unpersuasive reasoning when declining to intervene. On the other hand, in cases where prisoners have alleged that were being punished incompatibly with the European Convention on Human Rights, the UK judges and the judges of the European Court of Human Rights (‘ECtHR’) – particularly the latter – have adopted a more assertive approach. In so doing, they have interpreted Convention rights as they should: they have sought to place liberal constraints on democratic action, while also being careful not to move too far ahead of the popular will. However, recent charter overrides in the Australian State of Victoria – and Westminster’s hostility to the ECtHR’s decisions in the prisoner voting case of Hirst (No 2) v United Kingdom  IX Eur Court HR and the irreducible life sentence case of Vinter v United Kingdom  III Eur Court HR 317 – do show that ‘weak-form’ charters will not necessarily grant prisoners all of the benefits that the judiciary would confer on them. Nor would ‘strong-form’ charters certainly do a better job. This does not make human rights charters futile. It simply means that, while such charters can improve the position of prisoners, the extent to which they will do so depends on all the circumstances – including charter design and the political culture in the relevant jurisdiction.