By Ian MacWilliam
BBC News, Almaty, Kazakhstan
The main opposition contender in Kazakhstan's upcoming presidential elections, Zharmakhan Tuyakbai, says that high-level corruption is one of the main problems facing his country.
Mr Tuyakbai used to be the speaker of the Kazakh parliament
He told the BBC that contracts giving control of major national enterprises to people close to the president should be re-examined.
If these contracts are found to have involved corrupt practices, he said, the enterprises should be re-privatised according to the law.
Mr Tuyakbai is one of 11 candidates for Kazakhstan's presidential elections, scheduled for 4 December.
He represents a movement named For a Just Kazakhstan, an alliance of the country's main opposition parties.
It is unclear just how much popular backing the alliance has, but the country's weak opposition groups have always struggled for support among a post-Soviet population which is still largely apolitical.
Mr Tuyakbai will be running against the current president, Nursultan Nazarbayev, who has led Kazakhstan since before its independence from the collapsing Soviet Union.
Most of the other candidates are relatively unknown figures.
Mr Tuyakbai's call for a re-examination of privatisation deals echoes moves by opposition groups who have come to power in Ukraine and Kyrgyzstan, following the overthrow of incumbent presidents in those two post-Soviet republics.
"The money from the sale of natural resources today, or stolen by officials close to the president's family - that money doesn't go into the national budget," said Mr Tuyakbai.
"What's more, contracts for resource industries were often the result of corrupt deals, and these deals have damaged our national interests."
Kazakhstan is rich in oil, but only an elite few are said to benefit
"Those contracts should be re-examined to determine how legal they were," he added.
Accusations of corrupt business dealings by members of President Nazarbayev's family and inner circle are among the most politically damaging charges against the head of state.
Kazakhstan is rich in oil, minerals, land and other natural resources. But analysts say that many of the most profitable enterprises have fallen into the hands of a small number of people in the ruling elite.
Mr Tuyakbai also contends that Kazakhstan's political system must be changed to reduce what he says is an excessive concentration of power in the hands of the president.
"We need a change of political system," he said, "a change from an all-powerful president to a parliamentary-presidential system, where parliament will have the role it deserves, and where parliament will form the government and control the government's activity by overseeing the law and the budget."
The presidents of all the post-Soviet republics of Central Asia increased their own powers considerably through the 1990s, reducing their parliaments to little more than rubber stamps.
In neighbouring Kyrgyzstan, opposition leaders who came to power there in March have also said they want to give greater powers to the Kyrgyz parliament.
The new Kyrgyz government however, has yet to put forward a definite plan for constitutional change.
As Moscow, Washington and increasingly Beijing vie for influence in Central Asia, another lively political debate is which way Kazakhstan should look for its future development.
Historically Russia has been the dominant power in the region, but the opposition candidate says Moscow cannot provide a stable lead when its own political direction is now so unclear.
China and the Muslim countries of the Middle East are culturally too different from Kazakhstan, so Mr Tuyakbai thinks his country should look to the West.
And since the United States has its own geopolitical interests, Europe provides the best example for a way forward.
"Europe has never declared its interests and tried to exert pressure or influence in this region," he said.
"But it brings to this country the ideas and principles that we're seeking - equality, freedom, democracy and the example of the dignity of its own people.
"We should look to greater integration with Europe. That's the most appropriate for Kazakhstan."
During the election campaign, which officially gets underway on Tuesday, Mr Tuyakbai will have a difficult battle on his hands.
Among the president's challengers, Mr Tuyakbai certainly has the strongest credentials.
Until last year he was speaker of the Kazakh parliament and deputy chairman of the president's own party, Otan (Fatherland).
But following parliamentary elections a year ago, Mr Tuyakbai surprised the country by publishing an open letter in an opposition newspaper in which he said they had been rigged.
In the letter he alleged that media bias and pressure from local government officials had unfairly ensured Otan's sweeping victory, and he challenged President Nazarbayev to overturn the official results.
President Nazarbayev has been in power for 14 years
Mr Tuyakbai resigned from as speaker and also quit Otan, before resurfacing as a contender for the president's job himself.
He says the campaign system is skewed against the opposition since most local election committees back the president.
But apart from that, Mr Tuyakbai's real challenge is that he is standing against a president who, after 14 years in power, is still broadly popular.
Mr Nazarbayev has a solid record of leading Kazakhstan from a very uncertain independence to a position where its economy is growing strongly and where life, for most people, is getting better.
He will not be easily beaten.