A senior opposition official in Zimbabwe is alleging that President Robert Mugabe's Zanu-PF party has now split into "at least four factions".

So serious has factional fighting become within Zanu-PF that Mugabe, 92, last month described it as "treasonous". For a long time, party officials said there were no competing factions.

Eddie Cross of the Morgan Tsvangirai-led Movement for Democratic Change (MDC) said that the number of cracks within Zanu-PF was the main difference between the ruling party as it was in 2008 - when Mugabe lost the first round of presidential elections, but went on to win a dubious second round of voting - and Zanu-PF now, three years after Mugabe's most recent election victory.

Writing on his blog this week, Cross said: "[Zanu-PF] cannot be put back together in any sort of semblance of what it has been and no reconciliation is possible."

Until now, most media attention has been on two factions of the party: one led by presidential hopeful Emmerson Mnangagwa (who is currently a vice president) and an opposing faction known as the Generation 40 (G40). Mugabe's nephew Patrick Zhuwao supposedly belongs to this faction.

Discordant voices

Cross did not spell out how he believed the other two Zanu-PF factions had formed, or who was part of them.

Speaking last month at a million man march, meant to show what support Mugabe still enjoys, the longtime Zimbabwe leader said: "There should never be little groups to promote so and so. Those little groups are treasonous groups, they spoil the party."

"Let us not hear discordant voices from whomsoever. All this thing about factions is new to us, it destabilises the party," he added.

Factions within Zanu-PF became big news in 2014. That was when Joice Mujuru, the then-vice president, was summarily ousted for supposedly plotting to kill (or at least overthrow) Mugabe. In fact, said analysts, she'd become too popular and had so many supporters within the party that she represented a threat to Mugabe's continued hold on power.

Mugabe is clearly ageing, reportedly telling children at the weekend in a moment of uncharacteristic weariness: "I am on my way out."

But he has still not named a successor.

Opponents of the president shouldn't believe that the fractures in the ruling party are good news for them, however.

If Cross, who joined the MDC back in 1999, is to be believed, the Zimbabwe opposition is even more fractured. He says there are more than 30 different opposition parties.