Mongolia is preparing for national elections Sunday, pitting the former Communist Party, which is in power, against a coalition of opposition parties. Both sides have similar platforms, promising more jobs, less taxes and subsidies for the country's impoverished youth. But the issues seem hidden behind a giant wave of advertising and mudslinging.

A mostly college-age crowd rocks to the cream of Mongolia's heavy metal and hip hop bands Thursday night in Ulaanbaatar.

This is no ordinary rock concert, but a campaign rally for the ruling Mongolian People's Revolutionary Party, or M.P.R.P., the country's former Communist rulers, who are seeking to promote their new image as a left-of-center party for all generations.

On Sunday, the M.P.R.P. faces off in parliamentary elections against the Motherland-Democratic Coalition, a sometimes-fractious group of moderate parties that governed Mongolia from 1996 until the last elections in 2000.

Those elections took place amid a declining economy and several high-profile corruption scandals, and the M.P.R.P. won in a massive landslide, taking 72 of the country's 76 parliamentary seats.

Given the M.P.R.P.'s commanding majority, even members of the opposition admit they are unlikely to retake the government this time around, but they say a major gain in seats is not out of the question. How major, they say, depends on whether the elections are fair.

In the 14 years since its transition from Soviet-dominated autarchy to liberal democracy, the country that once sent its Golden Hordes to conquer much of the known world has won praise from the international community for its high level of freedom and pluralism.

But opposition campaign manager Puntsagiin Tsagaan says this year's elections are less than fair. He complains that the ruling party is using its advantage as the incumbent to dominate campaign advertising.

M.P.R.P. billboards vastly outnumber those of the Motherland-Democratic Coalition, as do television and radio ads on the state-run media.

M.P.R.P. campaign manager Yondon Otgonbayar rejects the opposition's claims that it is using its advantage to dominate the media.

"I think, we were simply better planned and better organized, and our opponents are coming up with their billboards [and] advertisements at a later stage," he said.

Some international election observers, like John Poepsel of the U.S.-funded International Republican Institute, say the lopsided media war may not matter that much. Mr. Poepsel says polls show most voters in Mongolia are sophisticated enough to vote on the issues, rather than the ads.

"The average Mongolian is very smart," said John Peopsel. "They know - when you see 10 M.P.R.P. signs on the road to every one opposition - they know what's going on."

Mr. Tsagaan of the Motherland-Democratic Coalition concedes that the advertising blitz may actually be working against the ruling party.

"Even the M.P.R.P. supporters are against these billboards, and the prime minister's nickname now has become 'billboard'," said Puntsagiin Tsagaan.

However, the opposition's Mr. Tsagaan makes a more serious allegation. He alleges that the M.P.R.P. is planning to commit outright election fraud.

He says the ruling party has had some of its supporters register more than once, and has limited the number of opposition election observers.

"For sure, five to 10 percent of the vote will be stolen [by the M.P.R.P.]," he said.

The ruling party denies the charge, and is making serious accusations of its own.

In an interview Thursday, Prime Minister Nambaryn Enkhbayar said the opposition is hoping to buy votes with cash.

"Many cars have left the city of Ulaanbaatar with a lot of cash, for the past two days, to prepare for the election day, when they will be trying to directly buy the votes," said Nambaryn Enkhbayar.

Mr. Enkhbayar says that, instead of spending money on advertising, the opposition has also been buying liquor to pass out to constituents, a serious charge in a country where voters are deeply concerned about rising alcoholism.

But Mr. Poepsel says despite the accusations, he expects the election to be mostly free and fair.

"Mongolia is more advanced than many other former Soviet countries," he said. "I like to think that Mongolia is a beacon of democracy in a part of the world that is traditionally less than democratic."

He says that, while there may be isolated cases of election fraud, they will be local, rather than acts organized by party officials, and will likely be no worse than similar incidents in Western countries.

In the end, he says, the outcome of the elections will depend more on the people's views of the politicians, than on ad campaigns or dirty tricks.

Ikhtaak, a young Mongolian woman attending the M.P.R.P.'s Thursday night concert rally, seems to agree.

She says she does not support the ruling party. She just came to its concert to take advantage of the free music, and to meet people.