Mr Makoni is standing as an independent candidate

"[It is] a polarised nation in deep stress and one characterised by disease and extreme poverty," he said.

If elected on 29 March as an independent candidate, he said he would start a process of reconciliation.

He said he was not against President Robert Mugabe, but urged ruling party members wanting "renewal" to join him.

Mr Mugabe is seeking a sixth term in office and told state media earlier this week he is "raring to go" in the polls.

Land reform urgent

At the manifesto launch in the capital, Harare, Mr Makoni said that he was not standing against the ruling Zanu-PF party, which formally expelled him this week, but "for the people of Zimbabwe".

SIMBA MAKONI Zanu-PF moderniser 1980: Named deputy minister aged 30 2002: Sacked as finance minister after argument with Mugabe 2002: Went to South Africa Possible support of Zanu-PF heavyweight Solomon Mujuru Trained chemist

Makoni's magic formula Diary: Election fever starts

He said that land reform was more urgent than ever - but it was necessary for rural development rather than a means of redressing the wrongs of the colonial era.

He urged Zanu-PF members to join him by standing in the election as independent candidates.

He also called on Zimbabweans living abroad to come home to vote.

The former finance minister claimed that since he had entered the contest last week, attendance at voter registration centres around the country had increased 10-fold.

No coalition

President Mugabe will face three presidential challengers as both factions of the opposition are also fielding candidates.

Mr Tsvangirai has said Mr Makoni is "old wine in a new bottle"

Earlier at a press conference in South Africa, opposition leader Morgan Tsvangirai confirmed his faction of the Movement for Democratic Change (MDC) would contest the election, despite what he called an uneven playing field.

He said that he would work with anyone who was prepared to close ranks against President Mugabe and the ruling party.

But the BBC's Peter Biles in Johannesburg says he gave no hint that he and Mr Makoni were about to form an electoral coalition.

Mr Tsvangirai pointed out that Mr Makoni had been a member of Zanu-PF's politburo while the Zimbabwean economy had been destroyed.

Previous polls have been characterised by violence and allegations of fraud.

Zimbabwe has the world's highest inflation rate - 26,000% - and only an estimated one adult in five has a job.

Mr Mugabe's critics blame the economic crisis on his policies, but he blames a Western plot to bring him down.