The ruling party of Kazakh President Nursultan Nazarbayev Monday won a landslide victory with over 80 percent of the vote in parliamentary polls which observers said failed to meet democratic standards.

Two nominally opposition groups won seats for the first time in the Kazakh parliament after Sunday's elections which veteran leader Nazarbayev hoped would breathe fresh life into politics while maintaining stability.

But the only clearly anti-government party -- the All-National Social Democratic Party (OSDP) which failed to make parliament -- denounced the elections as among the dirtiest ever in Kazakhstan and vowed street protests.

Nazarbayev's Nur Otan party won 80.74 percent of the vote in the polls, the central election commission announced.

"This is our shared victory," Nazarbayev told his supporters after the results were announced. "This means that the people of Kazakhstan will continue supporting our course of stability and unity."

Nur Otan will be joined in parliament by the pro-business Ak Zhol (Bright Path) party which garnered 7.46 percent of the vote and the Communist People's Party of Kazakhstan -- a largely pro-government group that won 7.2 percent.

None of the other four parties contesting the election in the resource-rich nation broke through the seven-percent threshold and will remain shut out of parliament.

International observers from the Organization for Security and Cooperation in Europe said the elections "did not meet fundamental principles of democratic elections" and had been marked by a lack of transparency in counting, as well as cases of electoral fraud.

"Genuine pluralism does not need the orchestration we have seen," Miklos Haraszti, the head of the Election Observation Mission of the OSCE Office for Democratic Institutions and Human Rights, said.

The OSDP -- the only force among the parties taking part to be openly critical of Nazarbayev and which polled only 1.59 percent -- said it would change its tactics to street protests from Tuesday.

"These were the dirtiest elections from a moral point of view that I have experienced," the OSDP's general secretary Amirzhan Kosanov told reporters in Kazakhstan's biggest city, Almaty.

"Tomorrow we will have a protest on Republic Square against these shameful elections. The polls have forced us to change our tactics and these will not be the only protests," he said.

The polls were overshadowed by concerns about Kazakhstan's stability after December clashes between striking oil workers and security forces killed 16 people in the Central Asian state's worst bloodshed since the collapse of the Soviet Union.

According to Nazarbayev, more than 70 percent of voters in the Caspian Sea city of Zhanaozen where the riots took place had cast ballots for Nur Otan in a sign of support for his rule.

Western monitors have never before recognised a Kazakh ballot as free or fair -- an issue that has irritated Nazarbayev's advisers as they position the region's largest economy toward future growth.

"If Kazakhstan is serious about their stated goals of increasing the number of parties in parliament, then the country should have allowed more genuine opposition parties to participate in this election," said the OSCE mission's special coordinator Joao Soares.

Observers had also condemned the conduct of the April 2011 presidential election that saw Nazarbayev win more than 95 percent of the vote in a poll where even one of his rivals voted for the Kazakh strongman.

But the president's chief political advisor Yermukhamet Yertysbayev brushed off the criticism from observers, saying the high turnout of over 75 percent was a simply a sign of strong voter mobilisation.

"I do not think it is right to reproach our elections for having a high turnout," he told the Interfax-Kazakhstan news agency.