By Daniel Wallis and Andrew Cawthorne
CARACAS, Dec 8 (Reuters) - Venezuelans voted in municipal elections on Sunday that were the biggest political test yet for President Nicolas Maduro as he tries to halt an economic slide and preserve the socialist legacy of his late mentor, Hugo Chavez.
The outcome of ballots to choose 337 mayors and about 2,500 councillors will be seen as a sign of Maduro's strength, nine months after Chavez died from cancer and he narrowly beat opposition leader Henrique Capriles to win the presidency.
"All patriots must vote so we can give a victory to our commander (Chavez) and guarantee peace and future for the fatherland," Maduro, 51, tweeted to supporters.
In Caracas shantytowns and elsewhere, pro-Maduro activists woke up supporters before dawn with bugle calls and trumpets in an election mobilization tactic begun under Chavez.
Queues were thin in the early hours but many polling stations stayed open beyond the scheduled 6 p.m. (2230 GMT) closure as numbers built up during the day.
Turnout of 60 percent or more was forecast.
Opponents portray Maduro as a buffoonish autocrat with none of his predecessor's political savvy and say his continuation of statist economic policies - including a new crackdown on businesses for alleged price-gouging - are disastrous.
"It's important to vote though I don't think it will bring the changes I want," said graphic designer Antonella Gutierrez, 45, voting at a primary school in a pro-opposition upscale suburb of Caracas nestled under the Avila mountain.
"I want changes from the presidency down. This government is tearing the country into bits, destroying my Venezuela."
Though local issues such as roads, street lights and utility services were bound to affect individual mayoral races, both sides in the polarized OPEC nation also see the overall results as a crucial show of their standing at national level.
First results were due late Sunday evening.
MIXED OUTCOME LIKELY
The ruling Socialist Party was likely to win a majority of municipalities thanks to its popularity in rural areas where most of the mayorships are located, while the opposition wants to keep control of big cities such as Caracas and Maracaibo.
Both sides were desperate to win the total popular vote, although most pollsters predict that would again be broadly split down the middle, like the April presidential poll.
That figure may not be available for days.
Opposition activists alleged some irregularities, including the use of state oil company PDVSA's vehicles to ferry pro-government voters.
Maduro, who has repeatedly accused opponents of planning trouble around the vote, warned there would be zero tolerance of any violent protests like the unrest that rocked Venezuela after his disputed election as president in April.
"I've taken measures to avoid any craziness by those who are always conspiring," he said when he cast his vote.
Investors are watching the ballot to see if Maduro will have the strength for unpopular moves, such as a currency devaluation that would help state coffers but also spur inflation.
Should the opposition perform well, its leader Capriles has vowed to "go for Maduro" but has not specified how.
The opposition's next opportunities to gain political ground are 2015 parliamentary elections and a signature drive for a recall referendum on Maduro in 2016. Some anti-government activists are pressing for more, like street protests.
Since taking office, Maduro, a burly 51-year-old former bus driver, has maintained core support among "Chavistas" by keeping his popular welfare programs and repeating his rhetoric and politics. But Venezuela's economic problems have worsened.
Inflation has hit 54 percent, scarcities of basic products from flour to milk have spawned queues and annoyance around the country, power cuts are frequent, and the bolivar currency has tanked against the dollar on the black market.
MADURO'S POPULARITY BOUNCE
The economic problems had been weighing on Maduro's ratings, but his recent aggressive drive to inspect shops and businesses suspected of price-gouging - and arrests of several dozen retailers - has proved popular among core supporters.
One poll by local company Datanalisis, leaked by Wall Street analysts, showed Maduro had received a 10-point bounce from last month to 50.4 percent popularity just before Sunday's vote.
Maduro says U.S.-backed and opposition-linked businessmen are behind an "economic war" intended to topple him.
In moves echoing Chavez's many clashes with the private sector, he has ordered companies to slash prices - delighting millions of consumers - and even sent troops to occupy a large electronics retailer he accused of price-gouging.
"The father of the revolution has gone, but he left the son who continued helping the poor," said pensioner Freddy Navarro, 62, who voted for a government candidate in downtown Caracas.
Opponents, and some economists, say Maduro's price-cutting measures smack of short-term populism that do nothing to fix what they consider the roots of Venezuela's economic mess: persecution of the private sector, inefficiency and graft in state businesses, an over-valued bolivar and excessive controls.
"The idea is to stay in power, not the development of the country or people's welfare," said Asdrubal Oliveros of local consultancy Ecoanalitica, often critical of the government.
Spicing up the elections, the government included several local celebrities on its mayoral roster, such as former baseball player-turned-rap singer Antonio "El Potro" (The Colt) Alvarez who was fighting for a Caracas district.
Voting appeared to be largely peaceful, though one newspaper reported a woman was shot dead in a queue in a western state.