Moscow: With less than a month left before Russia's parliamentary elections, approval ratings of the country's leadership tandem -- President Dmitry Medvedev and Prime Minister Vladimir Putin -- and the ruling United Russia party have dropped sharply.

Experts, however, have been unable to pinpoint specific events behind the decline.

A survey conducted by Levada Centre between October 28 and Nov 1 shows just 51 percent of Russians support United Russia, a drop of nine percentage points in just a week.

The popularity of Putin and Medvedev, who will lead the party in the Dec 4 voting, have dropped five percentage points each to 61 percent and 57 percent respectively since mid-October.

Levada Centre polled 1,600 people around the country. The results from state-run pollster VTsIOM paint an even gloomier picture.

It put Putin's approval rating at 42 percent and Medvedev's at 31 percent, a decline of six and seven percentage points since mid-October, respectively. The VTsIOM poll, conducted in late October, included 1,600 people.

“The latest ratings drop is difficult to explain, because no serious processes that could result in such serious dynamics are taking place now,” said Olga Mefodyeva of the Centre for Political Technologies.

While United Russia's election campaign is cause for 'irritation and sarcasm' among residents in some Russian regions, this was unlikely to have affected the party's national rating, she said.

The ruling tandem and governing party's popularity has gradually decreased since early 2010. In January last year, some 80 percent of Russians said they trusted Putin and 75-77 percent trusted Medvedev, according to various polls.

Medvedev and Putin announced in September their plans to exchange jobs after the presidential elections due in March 2012.

The announcement that Putin will run for President ended months of intense speculation about the incumbent prime minister's possible return to the Kremlin.

Medvedev, who succeeded Putin as President in 2008, agreed to replace Putin as Prime Minister in the country's next government.

(Agencies)