India, Aug. 6 -- More than 48 hours after Karnataka's Cabinet expansion, the lone vacant ministerial berth has become Congress leadership's key political decision, with competing demands over caste representation, factional equations and former chief minister Siddaramaiah's influence converging on a single unresolved appointment, leaders in the know said on Wednesday.

The uncertainty surrounding the 34th berth has also fuelled unrest within the ruling party, where disappointed legislators and their supporters have staged protests across the state over being left out of the ministry.

Leaders in the know said Siddaramaiah had personally recommended Byadgi MLA Basavaraj Shivannanavar for the remaining Cabinet position. His appearance along...