Mugabe -- who turns 84 years next week and has been the southern African nation's sole ruler since independence from Britain in 1980 -- is seeking another five-year term in the March 29 presidential, parliamentary and council elections.

The veteran Zimbabwe leader, who analysts had predicted was assured of victory against a weak and divided opposition, now has to contend with one of his senior ruling ZANU-PF officials, former finance minister Simba Makoni, in the presidential race.

"I am very raring to go and raring to fly," Mugabe said in remarks broadcast on state television on Tuesday, waving his trademark clenched fists in a sign of defiance.

Mugabe has said his party would secure a landslide election victory to silence the main opposition Movement for Democratic Change (MDC) and shame Western critics he accuses of funding his opponents to remove him from power.

But analysts say the entry of Makoni, a member of the ruling party's decision-making politburo, shows internal divisions in ZANU-PF which could leave Mugabe weaker even if he wins.

Makoni says he is backed by senior party officials who are however yet to publicly show their support.

The ZANU-PF politburo was expected to meet on Tuesday to finalise a list of candidates for the elections and take an official position on Makoni's move. The body also met on Monday but no decision was taken.

Some members of Mugabe's cabinet, including the agriculture, education and agriculture, engineering, mechanisation and irrigation ministers, have lost in the party primary elections.

Sabina Mugabe, the veteran Zimbabwe leader's younger sister who has been a legislator for more than two decades, said she would not stand for health reasons.

Analysts say shortages of food, foreign currency and fuel, and the world's highest inflation rate -- officially pegged at 26,000 percent -- are the biggest challenge to Mugabe's rule.

The MDC has failed to capitalise on Mugabe's failure to ease the crisis and it remains to be seen if daily hardships will push Zimbabweans to support Makoni.