Putin's party set to lose ground in Russia.

Prime Minister Vladimir Putin's party has seen its majority in Russia's parliament weaken sharply.

Preliminary results released today show the man who has steadily tightened his grip on the nation for nearly 12 years has suffered a humiliating setback.

Some opposition politicians and election monitors said even a result of around 50 per cent for Putin's United Russia party was inflated, alleging ballot-stuffing and other significant violations at the polls.

The party is still expected to retain its majority in the lower house and Putin is all but certain to win next March's presidential election, but yesterday's vote has badly dented his carefully groomed image. 

It reflected a strong public frustration with the lack of political competition, ubiquitous official corruption and the gap between rich and poor, which will pose a growing challenge to Putin's power.

With about 96 per cent of precincts counted, United Russia was leading with 49.5 per cent of the vote, Central Election Commission chief Vladimir Churov said.