Uncertainty increased in Zimbabwe on Wednesday over a disputed election as pressure intensified for results to be announced from a presidential vote more than three weeks ago.

Former colonial power Britain called for an arms embargo on Zimbabwe while analysts dismissed as unlikely a proposal that President Robert Mugabe should lead a unity government until new polls.

Prime Minister Gordon Brown said he would propose an arms embargo, joining calls by South Africa's Anglican church leader and Amnesty International. Brown repeated British accusations that Mugabe was trying to rig the elections and said this was "completely unacceptable".

Pro-government commentator Obediah Mukura Mazombwe introduced new uncertainty by suggesting Mugabe should lead a transitional government to end the deadlock while new elections were organised.

He said the solution should be mediated by Zimbabwe's neighbours. But analysts said Mugabe and his ZANU-PF party were pressing ahead with plans for a runoff vote against opposition leader Morgan Tsvangirai.

If adopted, Mazombwe's idea would delay even longer any outcome from an electoral process that Zimbabweans hoped would end their misery under an economic collapse that has saddled them with the world's highest inflation rate - 165,000 percent.

No results have been announced from a March 29 presidential vote which the opposition says it won, while the outcome of a parliamentary poll is also in doubt because of partial recounts. Officials said the first of 23 recounts had confirmed victory in one constituency for the ruling ZANU-PF party, which lost control of parliament for the first time in the election.

RECOUNTS

The recounts could overturn the MDC parliamentary victory.

Analysts said Mazombwe holds no position in the ruling ZANU-PF party and his comments may not have official backing.

"There is no likelihood of that. A government of national unity is highly unlikely if you consider ZANU-PF's hardening attitude and rhetoric," said Lovemore Madhuku, a Mugabe critic and chairman of the National Constitutional Assembly pressure group.

"That is reading too much into an opinion which does not reflect what we are witnessing on the ground," Madhuku said.

Tsvangirai's Movement for Democratic Change (MDC), human rights groups and Western powers accuse ZANU-PF of launching a campaign of post-election violence.

Tsvangirai says 10-15 MDC supporters have already been killed in the crackdown.

The opposition leader says he won the presidential election outright and Mugabe's 28-year rule is over.

The government has clearly indicated it expects a runoff - necessary if neither candidate wins an absolute majority. Such a vote would be held three weeks after the result is announced.

Further muddying the waters, Zimbabwe postponed an annual summit of Africa's COMESA trading bloc which it was due to host in the first half of May - suggesting the government may expect electoral developments in that period.

Cape Town Archbishop Thabo Makgoba called for a U.N. arms embargo against Zimbabwe, saying the plight of its people was heartbreaking.

He said the delay in releasing election results eroded "any remaining trust the people may have in the electoral process".

The South African army said there had been a clear increase in the number of people fleeing Zimbabwe since the election with almost 1,800 illegal immigrants caught at the border. Millions of economic migrants have already fled.

Zimbabwe's neighbours, previously passive despite the collapse of the country's economy, this week took a harder line towards Mugabe, refusing to allow a Chinese ship to unload arms headed for the landlocked country.

The United States has led international calls for Africa to do more to end the Zimbabwe crisis. Washington's chief Africa diplomat, Assistant Secretary of State Jendayi Frazer, was due in South Africa on a previously-arranged regional tour.

Archbishop Makgoba, in a clear reference to President Thabo Mbeki's softly softly approach to Zimbabwe, said South Africa's leaders appeared to many outside the country to be "heartless and unmoved by the suffering of Zimbabweans".