The party of South Sudan's president Salva Kiir has refused to accept an IGAD compromise proposal by which Riek Machar would become "First Vice President" and the incumbent vice president James Wani would be retained as a second vice president.

This issue is one of the points of disagreement that led to failure of the two sides to reach a power-sharing agreement last night and instead resulted in the signing of a less specific commitment to continue negotiating with a view to reaching a final deal by next month.

Last week the IGAD mediators proposed that SPLM-IO faction leader Riek Machar should become First Vice President, rather than taking the proposed position of "prime minister" as discussed at previous rounds. The mediators proposed Wani remain as a second deputy to Kiir.

Kiir and his negotiators rejected this.

They proposed instead that the two vice presidents should have equal status, according to an annotated version of the IGAD proposal used at the talks, seen by Radio Tamazuj. This annotated "working document" reveals that the original text of the IGAD proposal stated, "The SPLM/A (IO) shall nominate the First Vice President of the TGoNU."

However, this text is struck through and an alternative text proposed by SPLM-Juba is inserted. It says that the two vice presidents shall have "equal status."

For their part, the SPLM-IO negotiators preferred to stick to the IGAD proposal that Machar become the "First" Vice President.

File photo: Vice President James Wani Igga addressing an anti-UN rally organized by the South Sudanese government in March 2014