(CNN) -

In New York for the United Nations General Assembly, Georgian President Mikheil Saakashvili strides down the street at a brisk pace, his security details hustling to keep up, a man with a lot on his mind.

On Monday his country holds crucial parliamentary elections. The outcome will affect not only parliament but the structure of political power in Georgia, and the role of the presidency, almost nine years after the Rose Revolution brought Saakashvili to power.

Until recently, the ruling party, the United National Movement, has controlled much of political life in this country of 4.5 million people. Georgia has thrown off the shackles of its Soviet past. There are new, gleaming skyscrapers. According to U.S. and European officials, the Georgian government has made progress in the fight against corruption and has continued economic reform.

But critics, who have coalesced into the "Georgian Dream" alliance led by billionaire businessman Bidzina Ivanishvili, say reform is only skin-deep, charging that Saakashvili is pulling all the levers of Soviet-style "administrative measures." They have raised concerns about a level playing field for the opposition during this election, alleging harassment and limitations on their access to the media.

In an interview with CNN, however, Saakashvili claimed that he can guarantee that the elections will be free and fair.

"Not only I can guarantee that," he said, but "the international community says that they will be competitive, free and fair. That's what the preliminary reports of international organizations have clearly said."

He continued: "But I think the ultimate guarantor is our people. Our people have changed. I think they have moved beyond the stage where any ruler, any government official or any big money guy from the opposition can manipulate the results of the election."

That "big money guy" is how Saakashvili refers to the opposition leader Ivanishvili. The president accuses Ivanishvili of wanting to "buy the whole system," and sees the hand of Russia behind him, with which Georgia fought a brief but bitter war four years ago.

The president said he is concerned with the amount of wealth that Ivanishvili made in Russia, and that that money is being used to influence the elections.

"We know what Russian money is all about," he said. "How it was made, what kind of methods were used, and certainly it is a source of concern," he said.

Those charges are false stereotypes, Ivanishvili told CNN in a phone interview from the Georgian capital, Tbilisi.

A self-made businessman who made his money in Russia after the fall of the Soviet Union, Ivanishvili left Russia shortly after Vladimir Putin came to power.

His staff confirms his status as Georgia's richest man, with a fortune estimated at approximately $6.4 billion, equal to almost half of Georgia's economic output.

"It's not money and wealth which is my capital," he said. "It's trust from the people toward me. Money has nothing to do with this."

The billionaire said he has sold all his Russian assets, and defended his reputation.

"(Saakashvili) cannot find a single black spot," he said.

But the president insisted that not only the opposition leader but Putin himself is trying to undermine Georgia.

"Vladimir Putin said clearly that he is interested in the Georgian election outcome. He clearly said that he wanted the Georgian government out. He clearly said that he wanted me to be physically destroyed, he said it publicly," Saakashvili said.

Georgia's electoral waters have been roiled by a shocking video that emerged this month showing abuse in a Georgian prison, including one male prisoner being sexually assaulted. The opposition claims the video is proof of a repressive system put in place by Saakashvili and his government.

Saakashvili said his government acted quickly and decisively to the video, citing an investigation that has led to arrests.

"Not only were the immediate perpetrators arrested," he said, "but two government ministers resigned because they shared political responsibility for allowing the system to fail."

The torture shown on the video is no accident, but part of a system that is in shame, Ivanishvili said.

Thomas de Waal, an expert on Georgia and senior associate at the Carnegie Endowment for International Peace in Washington, said the video is significant, as the prison population quadrupled over the last eight or nine years.

"I do think it (the video) supports the opposition narrative that the government is arrogant and unaccountable, and this is obviously a war of two narratives over Georgia that we're seeing in this election," he said.

Georgia, which contributed troops to the NATO coalitions in Iraq and Afghanistan, is a strategic partner of the United States and its elections are being closely watched in the West.