As Bolivia's Evo Morales campaigns for re-election ahead of polls in December, his support from the nation's indigenous coca producers is again coming under scrutiny. Andres Schipani reports from La Paz.
Evo Morales is a champion for indigenous Bolivians
Many around the world see the coca leaf - the raw ingredient of cocaine - as a source of misery. For them, it stands for crack, cocaine and all the inherent evils of the illegal drugs.
But for indigenous Bolivians, the leaf is an intrinsic part of their ancient culture and economy. And it was partly to defend it that they voted four years ago for Evo Morales, the country's first indigenous president - and a man who himself grows coca leaf.
As his campaign for re-election gathers pace, the coca growers or "cocaleros" are backing him financially. The coca unions are combining to put money into his campaign, coming out of their harvest.
"I am backing President Morales with everything I can because he is one of us - an indigenous peasant, a coca grower, who knows what suffering means," says coca grower and trade unionist, Emilio Mamani, cupping a bunch of shiny green leaves.
"He is fighting for the rights of the indigenous poor, the peasants, that for centuries here were, basically, shadowed people."
The growers share a trade and passion with President Morales, who remains head of the country's largest coca trade union.
And they definitely want him to stay in office for another term.
"We are the backbone of this government, of this process of change. It is a huge responsibility we have, we coca growers," Sabino Mendoza, a young coca trade unionist and government adviser, told the BBC in one of the world's only two legal coca markets.
Since the mid-1980s, the coca growers have always been at the forefront of the political struggle in this country and have been key to President Morales's success, so he needs their support to cement his power base.
Industrial users of coca include the cosmetics and food industries. It is also used in traditional medicines, chewed, used in coca tea, and in some Andean religious ceremonies.
But there is a darker side to the coca growers' trade. In the past four years, coca production in Bolivia has increased. But, so too has the production of cocaine.
Since the start of his presidency in January 2006, Mr Morales has had a simple message for his followers: "Zero cocaine, but not zero coca."
But he admits there is a problem. "Lamentably, I, as a coca producer, have to tell the truth - the illegal price, the price of cocaine, is what regulates the price of coca. As long as it stays this way, illegal coca cultivations will keep mushrooming," he told reporters.
So the opposition has seized on cocaine production as a reason not to re-elect him.
"The only sector that has had an important growth in these past four years is the coca production and also the cocaine industry," Samuel Doria Medina, a wealthy businessman, who is one of the main contenders for President Morales's post, told the BBC.
"I would say that the main investments in this country have been in the cocaine business," he added.
However, despite four years of harsh political polarisation and the increase in drug production, there is still strong support for the man seen as the champion of the coca leaf and the indigenous masses.
Emilio Mamani says he is backing Mr Morales because he is "one of us"
Known as the "peasant president", the left-wing Mr Morales is favourite to win re-election in December. Recent opinion polls give him more than 50% support.
Riding strong support from the country's indigenous majority, Mr Morales won sweeping victories in a recall vote in August and a constitutional referendum in January.
Some analysts say it is perfectly valid that coca growers are backing him. Nor should it be an issue, says Jim Shultz of the Cochabamba-based think tank the Democracy Centre.
"It's no big surprise that the coca growers are backing Evo Morales, including with finances and other political support", said Mr Shultz.
"This is no different than large businesses supporting [former US President] George Bush financially when he ran for re-election or labour unions supporting Barack Obama in the United States when he ran. Political bases get out the vote, they contribute money, they do these kinds of things."
So, as the polls approach, the key question is whether Evo Morales is the coca leaf champion or the president who has let the rest of the country slide.
The split on this issue reflects the wider division between Bolivia's indigenous and non-indigenous people, and will play a large part in the way they vote in the presidential election.
But for coca growers such as Mr Mendoza, there is no discussion: "We, the coca growers, gave birth to this political process, to this revolution. It is an obligation to support our president with the product of our labour."