Reports that senior officials are making plans for President Robert Mugabe's departure have been denied by Zimbabwe's ruling Zanu-PF party.

Opposition leader Morgan Tsvangirai had told the BBC he had been approached with an offer of talks from two of the most powerful figures in the ruling Zanu-PF party.

He said, Parliamentary speaker Emmerson Mnangagwa and General Vitalis Zvinavashe, head of the armed forces, had wanted to discuss the possibility of forming a power-sharing government.

I was approached just before Christmas about possible negotiations Morgan Tsvangirai, Opposition leader

Click here to read the full interview

But Zanu-PF's spokesman Nathan Shamuyarira dismissed alleged talks being planned about Mr Mugabe's departure - also published in Britain's Times newspaper - as "wishful thinking".

"The British would like to see that happening but it is not going to happen," he told a news conference.

The BBC southern Africa correspondent Barnaby Phillips says it may be that Zimbabwe's desperate economic situation is pushing President Mugabe towards talks, but he says it seems extremely unlikely that he would contemplate handing over any power to an opposition which he views with contempt.

Conditions

Mr Tsvangirai, the leader of the Movement for Democratic Change, told the BBC's The World Today programme that he would be willing to consider an amnesty for Mr Mugabe as part of any possible deal.

But he said the deal would have to involve Mr Mugabe's stepping down, an "end of lawlessness", and free and fair elections.

He said his party was willing to negotiate with the government "provided Mr Mugabe stops the violence [against opposition supporters], stops politicising food distribution and returns the country to political normality".

Mr Tsvangirai demands free and fair elections

Although his party has in the past called for Mr Mugabe to be prosecuted for alleged human rights abuses, Mr Tsvangirai said the MDC would be willing to consider granting him immunity as part of any deal.

"The people have to decide," he said.

Peter Longworth, a former British High Commissioner in Zimbabwe, told the BBC he found Mr Tsvangirai's claims "very credible".

He described Mr Mnangagwa and General Zvinavashe as "people who can deliver" a deal.

Succession

Mr Tsvangirai said the offer might be related to a power struggle within the ruling party.

"The issue of succession [to Mr Mugabe] has not been resolved within Zanu-PF," he said.

Zimbabweans are facing famine

Zimbabwe's famine and economic crisis are worsening by the day.

The crisis was sparked by Mr Mugabe's programme of land seizures, and has been compounded by poor rainfall.

Previous internationally-backed plans for Mr Mugabe to go quietly have been vehemently rejected by the Zimbabwean president himself.

But our correspondent says it is likely he is aware of the alleged proposal.

The 78-year-old leader, who was re-elected in March 2002, is due back in the country on Monday after a two-week holiday in Thailand.

Talks between the MDC and Zanu-PF, brokered by Nigeria and South Africa, broke down in May last year after the opposition launched a legal challenge to President Mugabe's election victory alleging fraud.

Mr Mugabe has said he will only step down when his land reform programme has been completed.

From an original 4,000 white farmers, only about 600 now remain on their land.