A new draft constitution provision which bars Zimbabwean President Robert Mugabe from standing in the next election, which is expected to take place this year or next, has exposed internal Zanu-PF plots to oust its leader and triggered uproar in the faction-ridden party.

The situation has increased the stakes in the constitution-making process and shed light on the intensifying succession battle now playing out on the ongoing reform agenda.

The draft constitution clause which has caused a political storm states: "A person is disqualified for election as president if he or she has already held office for one or more periods, whether continuous or not, amounting to 10 years".

This means Mugabe, who has been in power without a break since 1980, would not be eligible to contest the next elections if the draft constitution is adopted through a referendum and parliament.

However, Mugabe and his loyalists are breathing fire over this provision and want it removed.

The Constitutional Parliamentary Committee (Copac), which is in charge of the process, was this week forced to retreat to an isolated venue in the eastern highlands to resolve the crisis. They met in Harare on Tuesday to discuss the issues but could not finish.

Zanu-PF Copac co-chairman Paul Mangwana, a senior party official, has been accused of "treachery" against Mugabe, although he has denied this and has been forced to come out publicly pledging support for his leader.

"President Mugabe has already said he is contesting the next elections. As long as I am in Copac, there is no way we are going to allow a draft which is detrimental to my party and its leader," he said.

Zanu-PF has tried to disrupt the drafting of the constitution in protest against the clause.

Mugabe's loyalists now want the constitution drafters, Judge Moses Chinhengo, Brian Crozier and Priscilla Madzonga, expelled over the issue.

Zanu-PF politburo member Jonathan Moyo described the drafters as "drifters drifting away from people's views" and demanded their dismissal.

Mugabe's loyalists have accused Copac officials and drafters of joining forces with Mugabe's internal enemies to block him from trying to extend his rule by another five years.

Given that senior Zanu-PF officials are involved in Copac and did not object to the provision initially, Zanu-PF now finds itself in turmoil.

Senior Zanu-PF officials who spoke to the Sunday Times said the move to prevent Mugabe from standing in the next elections started internally and was indicative of divisions in the party, as well as behind-the-scenes manoeuvres to oust him.

A senior Zanu politburo member said top party officials were behind the plan to "legislate Mugabe out of office".

"There is a group in the party which wants Mugabe out and has been working with Copac officials to use that provision to bar him from contesting the next elections," the official said.

During the 1999/2000 constitution-making process, Zanu-PF factions fought pitched battles over Mugabe's fate in an anticipated new constitutional dispensation.

One faction, led by the late Eddison Zvobgo, pushed hard to remove Mugabe through a draft constitution by inserting a provision which stated that anyone who had already served two terms of five years each would not be eligible to contest the next polls.

However, a group headed by Emmerson Mnangagwa fought against this and frustrated Zvobgo's bid to block Mugabe from standing again.

The constitution-making process is also deadlocked over the structures of government, devolution of power, the death penalty, gay rights, dual citizenship and the independent prosecuting authority.