Despite a growing body of literature on the advancement of autocratic tactics and toolkits in competitive authoritarian regimes (CARs), we lack sufficient knowledge on the strategies that the opposition builds against populist-authoritarian governments. Using two top autocratizing cases – Turkey and Hungary – this article singles out ‘transnationalization’ as one such novel strategy. ‘Transnationalization’ is defined as a strategy through which opposition-led subnational executives transform local and global boundaries by consciously forming a link with the liberal-democratic world in order to expand their space for manoeuvre. Conducting a qualitative content analysis of the Istanbul and Budapest mayors' international Twitter accounts and using evidence from elite interviews with officials from Istanbul and Budapest municipalities, we demonstrate the material, symbolic and political means of this strategy and the rationalist and normative motivations behind it. By discussing the what, how and why of a transnationalization strategy, we fill an important gap in the scholarship regarding opposition strategies in CARs.