Why do middle-income country governments use costlier sovereign debt markets when cheaper finance is available from official creditors? This research note argues that left-leaning governments with labor and the poor as core constituencies are likely to prioritize markets in their annual foreign borrowings. This is because markets provide an exit option from official creditor conditions that have disproportionately negative effects on working classes. This finding puts limits on disciplinary assumptions that left-leaning governments should have relatively less access to sovereign debt markets and thus use them less. Instead, left-leaning middle-income countries are likely to use proportionally more market finance as they fulfill annual foreign borrowing needs. This, in turn, shapes which middle-income countries are likely to become relatively more exposed to global debt market costs and pressures as they accumulate external debt over time.