BBC's From Our Own Correspondent dispatch from Liberia/ Sierra Leone

Tamasin Ford visits the centre of the country's diamond trade and meets some of the victims of its decade long civil war. To hear this report, clink on this link.

Ellen Johnson Sirleaf faces a tough presidential election in Liberia

They call her Ma Ellen, a fond nickname for Africa's most powerful woman. Ellen Johnson Sirleaf was the continent's first female president who took on a country ripped apart by 14 years of civil war. When she took office in 2005, Liberia's schools, roads and hospitals were in disrepair, the justice system was in tatters and many of the country's young people were skilled in just one thing: how to hold a gun.

Since then, Sirleaf has made impressive strides in transforming Liberia. She erased nearly $5bn (£3.2bn) in debilitating foreign debt in just three years. Foreign investment has returned. The annual government budget has risen sixfold from $80m to $516m. Winning the Nobel peace prize on Friday confirmed her heroic international status. But what is less clear is whether her success has trickled down to all of her people.

In Sugar Hill, a slum on the edge of one of Monrovia's bustling markets, a group of jobless young men sat lounging on crumbling brick walls. Many spend their days drinking 8PM, a strong Liberian gin, and smoking drugs. "For young men like me she hasn't done anything," declared 32-year-old Prince Flomo, a former combatant. "We put her there as president because we thought she was going to make things all right." He supported Sirleaf in 2005 but will not vote for her re-election in the country's second post-war general election on Tuesday.

Another young man declared: "Ma Ellen waived debt, that's true. She did well. But where's the development? Where's the jobs?"

Thousands of young men who fought during the 1989-1996 war still roam the streets "crooking" to make a living. Many came out of the disarmament process without the skills needed to find work. Some followed the lure of money across the border to fight in the civil war in Ivory Coast.

Many who voted Sirleaf in 2005 now backing the opposition Congress for Democratic Change (CDC) party. The CDC presidential candidate, Winston Tubman, was, like Sirleaf, educated at Harvard and is the nephew of Liberia's longest-serving president, William Tubman. His running mate is George Weah, the world-renowned football player who ran Sirleaf a close second in 2005.

Six years later, even as the vice-presidential candidate, Weah poses problems for Ma Ellen's re-election.

The announcement that Sirleaf had won the Nobel peace prize had little effect on the thousands of opposition supporters at the CDC's final election rally on Friday. "Muyan, muyan, muyan," they chanted – a battle cry for their beloved footballer, meaning "move forward".

But among opposition leaders, the prize has sparked resentment and recrimination. "It is undeserved," said Tubman. "It is a political interference in our country's politics."

One young voter said: "We thank God our pa now come because our ma fooled us."

Sirleaf is aware foreign investment hasn't yet brought much-needed jobs to Liberia. "It's difficult for them to understand that development takes time. That progress is incremental," she told the Guardian. Her government has attracted billions in foreign investment, and the first shipment of iron ore in 20 years left Liberia last month.

However, the average Liberian has yet to feel the benefits.

"They had a lot of confidence in me when I took over and they figured I would just turn things around. There would just be a quick fix, a magic wand, everybody would have a job," said Sirleaf.

Her government has been dogged by allegations of corruption and criticised for not doing more to tackle unemployment and restoring basic services such as electricity.

But the 72-year-old can still command an audience. At a campaign rally in a Monrovia church this month, the building was crowded with people trying to get a glimpse of their president.

"In the last six years we have done more than has been done here in the past 30 years," cried Sirleaf. "And we've done it with peace," she declared.

On the day she launched her campaign in the national stadium, the capital ground to a halt. She was forced to cut her speech short as people in the heaving crowds started fainting from the searing heat. As she toured the country on her campaign trail, roads became impassable.

In 2005, more than half of voters were women who turned out in high numbers to support Sirleaf, and she is relying on them to do the same thing on Tuesday. "The women's role has always played a big role. Their vote will be critical," said Sirleaf.

But women too are frustrated. Mamie Folay runs a small "cook shop" on the outskirts of Monrovia. A CDC poster hung from one of the peeling concrete walls of the small dark room.

Serving up bowls of rice to customers, she said: "I voted for Ellen but from 2005 up to now I can't get nothing to sustain myself."

Folay manages to make enough to feed her family but not enough to send her children to school. She complained of the soaring price of rice.The high cost of living has become a key issue in this election. Jewel Howard Taylor, the former wife of the ousted president Charles Taylor, is a popular figure among the women of Liberia. The senator from Liberia's third-largest county backed Sirleaf in 2005, but this time she too has switched allegiances.

"The first thing that's important to me are issues of the high level of poverty and unemployment and that's a high issue on the CDC agenda," she said.

Liberians historically vote along tribal lines so the existence of 15 other presidential candidates could take much-needed votes from Sirleaf.

One of those 15 is Prince Yormie Johnson, a former warlord, who in 1990 was filmed drinking beer while his men tortured and killed the ousted president Samuel Doe. Johnson eventually fled to Nigeria but when peace came Sirleaf chose not to have a war crimes tribunal in Liberia after the war, opting instead for a South African-style truth and reconciliation commission. Johnson reinvented himself as a born-again Christian and in 2005 was elected senator in the country's second largest county.

He is not expected to win but could help in forcing a run-off election in early November. If this happens, Sirleaf's re-election could be in the hands of the losing opposition parties. Their decision on where they pledge their loyalties could be crucial.

But Ma Ellen still believes she can win the election in the first round. "Ellen promised. Ellen is delivering," states one of her many billboards scattered up and down the country. But her success on Tuesday will depend on whether the promises she has kept can outweigh the ones she hasn't.