Polling opened Tuesday in Zambia's tightly contested vote to elect a president after a ruling party power struggle following the death of Michael Sata in office last year.

The two top contenders are Defence Minister Edgar Lungu, 58, representing the ruling Patriotic Front (PF), and opposition candidate Hakainde Hichilema, 52, of the United Party for National Development (UPND).

Lungu's party introduced the tax in January, while Hichilema has promised to scrap it, pledging a business-friendly Zambia.

The rivals -- Lungu the lawyer and Hichilema the businessman, affectionately known as HH -- drew huge crowds at last-minute rallies.

But in the absence of opinion polls, some analysts hedged their bets.

"It's a two-horse race," said Oliver Saasa, CEO of Premier Consult, a business and economic consultancy firm. "It's quite clear this is a very closely run race."

Others were more certain.

Analyst Neo Simutanyi of the thinktank Centre for Policy Dialogue said: "We can safely conclude that the opposition will win this election, but I don't think the margin will be very wide."

Election-weary Zambians, who voted in scheduled elections that brought Sata to power three years ago and are also due to cast ballots next year, formed long queues despite early morning cold weather.

Infighting in Sata’s wake

Hichilema's camp is seen to have received a boost from the infighting within another major opposition party, the Movement for Multiparty Democracy (MMD), whose candidate Nevers Mumba is given little chance.

Lungu's Patriotic Front went into the vote badly fractured by a bitter power struggle after Sata's death in October, just three years into his five-year term. Two opposing camps -- one led by Lungu and another by interim president Guy Scott -- nominated rival presidential candidates. After many weeks of mud-slinging, Lungu emerged as the sole candidate -- but of a weakened party.

Scott, Africa's first white leader in 20 years, cannot stand for the presidency himself as his parents were not born in Zambia.

With ideological differences between Zambia's political parties difficult to pin down, voting patterns are often determined by personalities and ethnicity rather than issues.

Despite growth-oriented policies and a stable economy over the past few years, at least 60 percent of Zambia's population of about 15 million lives below the poverty line, according to World Bank figures.

About 5.2 million people are eligible to cast ballots.

Polling opened at 6:00 am (0400 GMT) and is due to close 12 hours later across 6,000 polling stations.

(FRANCE 24)