EU focus of Czech elections

Former PM Klaus is fighting to regain the top job

PRAGUE, Czech Republic (CNN) -- Czech voters are casting their ballots to select a new parliament, which should determine the country's next prime minister.

In a tightly fought campaign, the emphasis has often dwelt on how the two key political rivals view the EU.

Pre-election polls show voters almost evenly divided between parties of the left and right.

The ruling centre-left party, the Social Democrats, led by Vladimir Spidla and the centre-right Civic Democratic Party, led by former Prime Minister Vaclav Klaus, are both polling around 25 to 30 percent. (Profiles and issues)

EXTRA INFORMATION Key players and election issues  Parties and policies

The most recent polls do show the Social Democrats with a slight edge, but it is within the margin of error, making the race too close to call.

Despite big differences over issues and ideology, the Social Democrats' minority cabinet has been tolerated in government by the Civic Democrats for the last four years under a controversial deal known as the "opposition agreement."

Trailing in the most recent polls are the grouping of centre-right parties, known as the Coalition and the Communist Party.

They have been hovering around 15 percent.

Because the top two parties have worked together in government since the last election, they have worked hard to highlight their differences in this election. (Parties and policies)

For example, the Civic Democratic Party wants to create a 15 percent tax and change the pension system to create personal retirement savings accounts.

The Social Democrats plan to increase some social services, support unionisation, and create 200,000 jobs.

Both leading parties say they are for membership of the European Union -- although the Civic Democratic Party says the EU has to meet some key conditions first.