Uruguay is struggling to roll-out the commercial production and sale of marijuana and its ground-breaking experiment could be dropped or watered down if an opposition candidate wins this month's presidential election.
The South American country is the world's first to permit the cultivation, distribution and use of marijuana, aiming to wrest control of the trade from drug gangs while at the same regulating and even taxing its consumption.
The reform is being followed closely across Latin America where the legalization or decriminalization of some narcotics is increasingly viewed as a better way to end the violence spawned by drug trafficking than the U.S.-led "war on drugs."
But first Uruguay needs to work out how to ensure criminal gangs do not finance producers, how to regulate the supply and quality of locally produced marijuana, and how to satisfy neighboring states that legally grown dope will not be sold illegally on their streets.
The government has missed its own deadlines in implementing the changes that were passed into law last December.
"We've been working on this since the very beginning, since the first day. But I just don't know if we'll manage it " said one government source familiar with the legalization program.
Sebastian Sabini, a lawmaker of the ruling coalition who put forward the law, said its implementation required the creation of institutions that existed nowhere else.
The plan to start selling marijuana in pharmacies late this year looks unlikely as the government is still tendering cultivation licenses and identifying where seeds can be purchased from.
Given the delays, leftist President Jose Mujica now faces a race against time to push through the changes before the country's next leader takes office in March.
Voters go to the polls to elect a new president on October 26.
Mujica, a 79-year old ex-guerilla, is constitutionally barred from running for a second consecutive term.
The candidate for the left-wing Frente Amplio ("Broad Front") ruling coalition, Tabare Vazquez, has endorsed the marijuana law, though he is less enthusiastic about it than Mujica.
Vazquez's main opponent in the tight race, Luis Lacalle Pou of the centrist National Party, endorsed a bill in 2010 that would have allowed personal cultivation of marijuana but he says the current reform is "inapplicable in reality."
"I am against the state producing and selling drugs and earning money with this," he said.
Lacalle Pou, who is the son of a previous president, told TV station Canal 10 the law would be difficult to implement, adding it meant the state "abandons its role of protecting public health and trying to prevent addictions."
If Lacalle Pou wins and the marijuana law has not been rolled out, he could simply shelve the project. Otherwise, he would have to pass a new bill overturning it.
The Netherlands permits the sale of marijuana in "coffee shops," Canada allows terminally ill patients to grow and smoke their own marijuana and the U.S. states of Washington and Colorado have legalized its cultivation and consumption but only Uruguay has passed legislation to allow commercial production.
Uruguay is one of Latin America's most liberal societies and smoking marijuana has been legal here since 1998.
Even so, opinion polls ahead of the election have shown almost two out of three Uruguayans disapprove of the state playing the role of narcotics regulator.
Mujica's critics say his liberal policies, which also include the legalization of abortion and gay marriage, have often been more widely acclaimed abroad than at home.
An opinion poll by consultancy group Factum earlier this month showed Vazquez with the support of 42 percent of voters and Lacalle Pou in second place with 32 percent.
With both men projected to fall short of the absolute majority needed for a first-round victory, they will likely go to a runoff, where polls show them running neck-and-neck.
Vazquez, 74, has been largely silent on the marijuana issue and, while Lacalle Pou has reiterated his opposition to the law, it has not flared into a hot campaign issue. Voters are more concerned about crime, health and education.
The marijuana legislation allows each household to grow up to six plants while registered users may buy up to 40 grams per person a month at pharmacies.
Out of an estimated 150,000 recreational smokers, however, only 600 have registered to be allowed to grow cannabis at home.
One of them, civil servant Renzo Dodera, 49, welcomes the change, recalling how police last year destroyed his crop after a neighbor snitched on him. But he says the law has left some pot smokers feeling uncomfortable.
"They feel the register can be a way of keeping track of cannabis users in a system that still discriminates against them," said Dodera. "They are worried it may make it impossible for them to get work."
Pricing has proved to be another headache. Uruguay wants to undercut cheap Paraguayan cannabis that is often mixed with dirt and sell top grade marijuana that sells at nearly $4 per gram on the street for just $1.
At those prices, some producers may decide there is not enough profit to make it worthwhile. Uruguay received 22 applications for commercial production licenses after there were about 100 initial inquiries.
Still, some smokers back the government's moves and say they are unfazed by the risk of Mujica failing to see through the law before he steps down.
"We have been fighting for this for 10 years," said Juan Vaz, chairman of the Association of Cannabis Studies of Uruguay and the first Uruguayan to register as a marijuana grower in August. "We're in no rush."