Mexico's Institutional Revolutionary Party (PRI), which has ruled the country for 71 years, next week faces its greatest challenge to date. It is running neck and neck with the centre-right National Action Party (PAN) in the presidential elections on July 2nd.
The latest poll gives the PRI candidate, Mr Francisco Labastida, 42 per cent of anticipated preferences, compared to 39 per cent for his PAN rival, Mr Vicente Fox, with a margin of error of 2.5 per cent.
"If the election is fair then Fox will win," said one PAN supporter, as the PRI turned to male strippers and state handouts to secure last-minute votes.
The Federal Electoral Institute (IFE), responsible for overseeing the election, has received thousands of complaints of vote manipulation, mainly in rural areas.
In Yucatan state the PRI gave away 1,000 washing machines this week, while investigators yesterday found 15,000 food packages in a warehouse in northern Mexico allegedly due to be handed out before polling day.
In Chiapas 300,000 families have received a state subsidy which came with a pamphlet supporting Mr Labastida, while workers at the state oil giant, Pemex, complained they were ordered to vote for the PRI or risk losing their jobs.
Such threats sound absurd in a country where the ballot is universal and secret, yet farmers in rural areas still fear that their preference will be discovered.
The IFE director, Mr Jose Woldenberg, has acknowledged that "most Mexicans prefer a kilo of rice to a vote", a hint of the difficulties in opening up Mexico to multi-party politics.
"Take what you can but vote for the PAN" was Mr Fox's pragmatic response to the PRI electoral handouts.
In a more sinister development, a farmer who heckled a PRI candidate for parliament at a rally in Oaxaca this week was detained by police and found hanged in his cell hours later, his body bruised and beaten. Human rights groups have called for an investigation.
Mr Fox's campaign strategists are working feverishly to poach votes from the third-placed candidate, Mr Cuauhtemoc Cardenas, who enjoys just 15 per cent of voter preferences.
Many Democratic Revolutionary Party (PRD) supporters are throwing their vote behind Mr Fox, the only candidate with a chance of toppling the PRI. A former Coca-Cola executive with a penchant for cowboy boots and saloon-style humour, Mr Fox has appropriated the PRD's policy in Chiapas state, pledging to fulfil the San Andres peace accord. The accord guarantees respect for indigenous autonomy, a significant incentive to PRD voters.
The PAN has also been accused of using dirty tricks in its campaign battle, with tonnes of hot chillies burned beside a PRI rally in Yucatan province, equivalent to 100 tear-gas grenades. The fumes effectively sabotaged the event.
The pro-Catholic PAN has a track record of intolerance in office, banning mini-skirts and plays in areas where it governed. Mr Fox, however, represents a more liberal wing of the party, causing a scandal earlier in the campaign when he compared the hegemony of the Catholic Church in Mexico to the PRI itself, a strategy aimed at winning evangelical votes.