Harare - In an unusual development, President Robert Mugabe’s ruling Zanu-PF party is to hold a special congress this December ahead of elections in 2018. The extraordinary congress has been brought forward by two years. Here’s what Zimbabwe analysts are saying: Mugabe won't step down – but Grace could step up Analysts say that Mugabe wants to use this congress to entrench his family’s hold on power. That could mean a new position as vice president for Grace, the first lady. Under the party’s constitution, one of the vice presidents has to be a woman. That hasn’t been the case since Joice Mujuru was sacked, at Grace’s instigation, in 2014. Backed by supporters of the G40 faction, Mugabe could use this congress to get Grace Mugabe elected. Mnangagwa may be pushed out… There’s some speculation Mugabe and his supporters (and Grace) could use the congress to push out Vice President Emmerson Mnangagwa, the man so long seen as Mugabe’s favoured successor. Grace has been increasingly vocal in her criticism of Mnangagwa in the last few weeks. Or Mugabe may choose to keep him Analyst Takavafira Zhou said that those aligned to Mnangagwa "may be mooting an idea of resisting the dynasty" and could "show their force at the congress". Mnangagwa has many backers within the ruling party’s old guard. Alienating them and their allies within the war veterans and security establishments could be risky for Mugabe, says another analyst, Pedzisai Ruhanya. In the past, the war veterans have been "critical instruments of coercion". Mugabe may decide he can't afford to have them in the opposition with elections just round the corner. The opposition could capitalise on Zanu-PF divisions... "It’s not a done deal that Mugabe will win in 2018," says Ruhanya. He said there are three things that are extraordinary about this 'extraordinary' congress: "He [Mugabe] is getting old, his wife is ambitious and he is betraying his old friends who want to ascend to power."Given that, Mugabe could face resistance from within his own party, and this would benefit the opposition. At the moment though, the opposition is severely weakened with MDC leader Morgan Tsvangirai recently hospitalised from cancer and little evidence that opposition supporters are being mobilised to register to vote. But it looks unlikely Plans for an opposition alliance to oppose Mugabe seem to be at a standstill. "The prospect of a united opposition to face Mugabe is all but diminishing," said the private NewsDay paper in an editorial. Is victory for Zanu-PF a foregone conclusion whatever happens at December’s extraordinary congress? We will know next year.