A HUGE debt burden remains a major impediment to attainment of sustainable socio-economic development of the Common Market for Eastern and Southern Africa (Comesa) members, said vice- president Christon Tembo on Monday. Tembo, opening the sixth Comesa council of ministers meeting in Zambia, said most of the organisation’s member states used over 50% of their national earnings for debt service. “Most of the Comesa member states are least developed countries by the United Nations classifications and are also the most highly indebted countries in the world,” Tembo said.