It is not known where Machar is although sources believe he is in South Sudan.
On Wednesday, three SPLM factions currently in Juba with the exception of the faction led by Machar announced that they have reunified according to a statement issued by the ruling faction spokesman Peter Lam Both.
Speaking to journalists on Thursday, the government official who requested anonymity said although he has not confirmed 100 percent, Machar has only one month to come to Juba or risk missing the reunification deadline.
“I think – I am not 100 percent sure about what will happened next – but Machar has one month to report to the capital to join the reunification process,” the senior SPLM official told the media.
He said he cannot disclose what will happen next if Machar decided to ignore the one-month ultimatum.
“I am not sure and I cannot disclose what will happen next if he failed but he has one month to come here,” added the official.
The SPLM-Juba spokesman Peter Lam also said in the same statement on Wednesday that those who are not in the country will apparently be given one month to report to Juba to take up their positions in the party or be replaced.
The SPLM is the Sudan People’s Liberation Movement, South Sudan’s ruling party, which fractured in December 2013 following violence at a convention at Nyakuron cultural centre.
The violence and the disagreements within the SPLM party led to fighting within the politicized South Sudanese army, igniting the civil war.
In January 2013, SPLM factions signed a reunification accord in the Tanzanian town of Arusha to work together again.