* Mugabe preaches peace on election eve
* Veteran describes campaign as "energy-sapping"
* Police out in force in Harare townships
* Tsvangirai urges observers to take tough line
* Disputed result, political crisis seen likely
Setting aside weeks of campaign trail acrimony, Zimbabwe President Robert Mugabe buried the hatchet with political rival Morgan Tsvangirai on Tuesday, the eve of a hotly contested election that remains too close to call.
Flanked by his defence minister and two stuffed lions in the colonial grandeur of State House in Harare, the 89-year-old leader likened the run-up to the July 31 vote to a boxing bout that ends in a handshake, not bloodshed.
"I've got my fair share of criticisms and also dealt back rights and lefts and upper cuts. But that's the game," Mugabe said, mimicking the movements of a boxer as he sat behind an ornate wooden table on the front steps of the mansion.
"Although we boxed each other, it's not as hostile as before," he said. "It's all over now. We can shake hands."
His words are in marked contrast to the cut and thrust of what he described as an "energy-sapping" campaign, and may go some way to soothing the fears of Zimbabwe's 13 million people of a repeat of the violence that broke out after Mugabe lost the first round of an election in 2008.
With no reliable opinion polls, it is hard to say whether the 61-year-old Tsvangirai - now prime minister in a fractious unity government - will succeed in his third attempt to unseat Mugabe, who has run the southern African nation since independence from Britain in 1980.
Both sides are forecasting landslide wins but the bigger question is whether the loser will accept the result of a poll dogged by logistical problems and allegations of vote-rigging.
Asked if he and ZANU-PF would accept defeat, Mugabe was unequivocal: "If you go into a process and join a competition where there are only two outcomes, win or lose, you can't be both. You either win or lose. If you lose, you must surrender."
A spokesman for Tsvangirai's Movement for Democratic Change (MDC) said the party was prepared only to the accept the results if the poll was "free and fair" - a verdict on which the jury is still out.
Around 200 supporters of Tsvangirai's Movement for Democratic Change (MDC) were killed in 2008, and memories of the violence remain raw in the impoverished townships that ring the capital, the epicentre of opposition to Mugabe's 33-year rule.
With one day to go before the vote, security forces were taking no chances, sending squads of heavily armed riot police into the restive districts of Mbare and Highfield on the outskirts of Harare.
State radio said thousands of officers had also been sent to the central Midlands province, another potential flashpoint in the presidential and parliamentary race that brings the curtain down on the four-year unity government set up after 2008.
So far, the campaign has been marked by allegations of threats and intimidation but there has been no violence.
Western election observers have been barred, leaving the task of independent oversight to 500 regional and 7,000 domestic monitors. The final results must be released within five days but may come sooner.
In an editorial in the local News Day newspaper and the Washington Post, Tsvangirai urged African monitors not to give the vote a seal of approval merely because they do not witness bloodshed.
"Mugabe is the world's oldest leader and one of its longest-ruling dictators. He is fixing this election in a more sophisticated fashion than previous ZANU-PF campaigns of beatings, killings and intimidation," he wrote.
"Mugabe's election-stealing antics have been documented throughout Zimbabwe and beyond. Yet the international community seems apathetic; perhaps Mugabe has been stealing elections for so long the world just rolls its eyes and moves on."
Mugabe acknowleged problems with the election organisation, including the late release of the voters' roll, but denied his minions had doctored the list to ensure a ZANU-PF victory.
"I don't control the electoral process. I comply with and obey the electoral law," he said.
Given the problems that have dogged the process, many Zimbabweans expect a lengthy post-poll dispute that will start in the courts but could spill over onto the streets.
"A return to protracted political crisis, and possibly extensive violence, is likely," the International Crisis Group, a Brussels-based political risk think-tank, said in a report issued on Monday entitled "Mugabe's Last Stand".
The 2008 deadlock was broken by a unity government brokered by South Africa but Mugabe ruled out another compromise outcome with a man with whom he has struck up a cordial working relationship that includes tea and cake on Monday afternoons.
"That circumstance is not envisaged this time. I don't think we will have the same result," he said.
The verdict of observers is crucial to the future of Zimbabwe's economy, which is still struggling with the aftermath of a decade-long slump and hyperinflation that only ended in 2009 when the worthless Zimbabwe dollar was scrapped.
If it gets broad approval, there is a chance that Western sanctions may be eased, allowing Harare to normalise relations with the IMF and World Bank and access the huge amounts of investment needed to rebuild its dilapidated economy.
In a parting remark, Mugabe, who is often depicted in the West as a tinpot African dicatator, asked for the outside world to judge him fairly. He could also not resist another dig at his arch-enemy: former British Prime Minister Tony Blair.
"If Mugabe is a thief, a robber, say so. But if Mugabe is right, and Blair is wrong, say so," he said.