Over the past decade, a third wave of autocratisation has stormed the world, hitting democracies and autocracies alike. The ongoing democratic backsliding is attributed to a range of factors. From “executive aggrandisement” and strategic manipulation of elections to "autocratic lawfare”. Such autocratic tendencies are contributing to autocratisation in dominant party regimes in Africa. If most dominant party systems are increasingly autocratising in Africa, then there is a problem with the dominant party structure that warrants academic inquiry. However, the literature on one-party dominance and democratic consolidation in Africa are a bit old, hence do not address the current debates on democratic backsliding in the continent. Botswana and Tanzania are interesting cases of autocratising dominant party systems because they have witnessed rapid erosion of democratic qualities over the decade. But what effects do these patterns of democratic backsliding have on the quality of democracy in dominant party systems in Africa? Employing a comparative research design (MSSD) and using historical institutionalism and the substantive democratic theory as well as relying on secondary data in Botswana and Tanzania (Mainly Afrobarometer surveys, V-Dem Index, CPI Index, Ibrahim Index of African Governance, and Freedom Index), this study explores this question within the framework of peace and development research. It analysed four variables: management of social tensions facing the regime, the scope of presidential power, governance performance, and the nature of the electoral competition. Findings suggest that a dominant party structure in Botswana and Tanzania creates conditions that erode the quality of democracy, hence democratic backsliding. Therefore, the thesis argues that autocratisation in Botswana and Tanzania suggests reproduction of one-party dominance at the expense of consolidation of substantive democracy. This way, a dominant party structure in Africa appears to be a peace and development research problem because it creates strong incentives for dominant parties to autocratise rather than democratise when challenged by a strong political opposition.