Haji, who has run on opposition tickets in Tanzanian presidential elections in the past, was Minister of Infrastructure and Communications until Lowassa defected. 
Haji, ambaye katika chaguzi za miaka kadhaa iliyopita amekuwa akigombea kwenye nafasi za kitaifa kwa tiketi ya vyama vya upinzani, alikuwa waziri wa Uchukuzi na Mawasiliano hadi kipindi Lowassa anaihama CCM.