Simba Makoni, a former finance minister and senior ZANU-PF official who will compete with Mugabe for the state presidency on March 29, said on Thursday he was confident of victory. He told journalists he was leading "a movement" in a bid to end nearly three decades of Mugabe's rule.

"Let me encourage those others in ZANU-PF who have been, and are still working with us in this project for national renewal, to remain steadfast and not be intimidated ... for the dawn of a new beginning is upon us," Makoni said.

Makoni insisted he was still a member of ZANU-PF, despite party announcements on Wednesday that he had effectively "expelled himself" from the party by challenging Mugabe.

"Which section or article of ZANU-PF's constitution provides for self-expulsion? I haven't seen it," Makoni said, adding he would continue in his position as a member of the party's top policy-making body, the politburo.

"I plan to continue my functions as a member of the party until I'm expelled by due process. I don't take a TV announcement or newspaper write-ups as due process under the constitution of ZANU-PF."

Makoni dismissed allegations -- mainly in the state media -- that his move to challenge Mugabe was funded by the West.

Mugabe brands the main opposition Movement for Democratic Change, his most serious challengers to date, puppets in a British attempt to oust him for seizing white-owned farms for blacks. "Any different ideas are regarded as antagonistic and foreign," Makoni said, dismissing suggestions that his campaign was a ploy by ZANU-PF to confuse the electorate and split the opposition's predominantly urban vote.

"I declare here I am genuine, I am honest, I am nobody's tool or agent. I am Simba Makoni."

Makoni -- regarded as a reform-minded technocrat -- has for years been touted as a possible successor to Mugabe, although critics say he lacks a political base of his own.

Mugabe says he will run for another term to shame his detractors, who accuse him of ruining what was once one of Africa's brightest economic hopes but is now saddled with the highest inflation rate in the world, more than 26,000 percent.