The road to the border runs through what was once prime fruit-growing land, through the bush where vast herds of cattle grazed, down to the frontier where lorries thundered through, piled high with the fat of Zimbabwe’s land, for export to a hungry Africa.

Now the only lorries are empty fuel tankers, heading to South Africa to fill up with the petrol that few back home will be able to afford. Cars trundle across on weekly shopping trips, bringing back the basic foodstuffs that Zimbabwe once exported in abundance. And off the road, where crocodile-infested streams run through a bush patrolled by armed border guards, another desperate soul tries to cross, joining four million Zimbabweans in exile in search of earnings to send back to their hungry families.

This is where, last month, Robert Mugabe, Zimbabwe’s hero of independence and its only leader in the nearly three decades since, began his campaign to be reelected for the next five years. It was his 84th birthday. President Mugabe has ruled this country for so long that his presence seems an inescapable reality, an unchanging part of a changing landscape.

This time, however, for the first time since independence, his victory is no longer a given. In today’s election, Comrade Mugabe, Uncle Bob, or simply the “old man”, faces the toughest battle of his political life. “He was the hero of the liberation struggle, just as he says,” Philip Chiro, a bricklayer and former Mugabe supporter, said. “But now our struggle is simply to survive and if he does not go, I believe Zimbabwe will die.”

Mr Chiro had come to the stadium in Bulawayo to see one of Mr Mugabe’s biggest challengers. Not Morgan Tsvangirai, the long-time opposition leader, who has battled the regime for a decade, but Simba Makoni, the former Finance Minister and senior member of the Zanu (PF) politburo, who was spectacularly flung out of the party last month when he broke ranks and offered himself up as a candidate against Mr Mugabe.

“Until then, the election was dead in the water,” said David Coltart, the MP for Bulawayo South, and a leading member of Mr Tsvangirai’s Movement for Democratic Change until the party split two years ago. The schism cast a pall of gloom over the opposition, already downcast over Mr Mugabe’s blatant theft of the 2002 and 2005 elections, which was ignored by Zimbabwe’s neighbours, reluctant to turn on a hero of black liberation.

Mr Makoni’s emergence threw up new, previously unthinkable scenarios. He is known to have the tacit allegiance of much of the intelligence and security apparatus, the very people Mr Mugabe has relied on to steal votes for him in the past. What if the rigging, instead of returning the President, were to go in favour of his renegade former minister? What if others from the ruling party defected to his side at the ballot box. What if, rather than splitting the opposition vote, he took it from the ruling party itself? And so to the next, daring thought: what if this were the end of the road for Mr Mugabe?

The Mr Mugabe that Mr Chiro remembers was a hero once. When he stood beside the Prince of Wales in 1980 as the old Rhodesian flag was lowered and the new Zimbabwean standard was raised, the new leader vowed that blacks and whites would stand together and leave the brutal past behind to build a nation together. But within two years, he had turned on his own people, launching the Gukurahundi, or “the rain that washes away the chaff”, a series of massacres against supporters of the Zapu party, which had fought alongside Zanu (PF) in the war against white rule. The Government claimed that only 400 dissidents died, but 20,000 people were killed across Matabeleland in the west of the country. Bulawayo is its main city.

Hundreds of schools and hospitals were built elsewhere during that decade, and into the Nineties, as Zimbabwe prospered. Dumiso Dabengwa, the former Zapu intelligence chief, served as Mr Mugabe’s Home Minister during that period, despite having served time in prison for treason. He remembers a committed and conscientious leader, poring over the details of every document that he was given.

As time went on, Mr Mugabe wavered. “He would make excuses, he was no longer committed,” Mr Dabengwa told The Times at a clandestine meeting in Matabeleland. Foreign journalists are barred from reporting in Zimbabwe and those here operate under the radar. “He was getting too old, he had too much on his plate.” Discontent began to brew within the party and there was talk of reining in the President.

Then Mr Mugabe launched his plans to seize white-owned farms. Most of the party backed the idea of land redistribution – the situation at independence was blatantly inequitable, with 90 per cent of the country’s most productive land in the hands of 5,000 white farmers.

But many watched in horror as he unleashed the war veterans in a violent campaign to seize the farms, handing them not to landless peasants but to friends, families and cronies. By now, Mr Dabengwa said, Mr Mugabe was so out of touch that he may not even have been aware that governors were plundering the farms and handing land to their own families. “He didn’t want to know the truth, and the people around him just told him what he wanted to hear,” he said. “He had lost touch with reality.”

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