Thousands of supporters of Russian Prime Minister Vladimir Putin rallied on Saturday to back his bid to return to the Kremlin, a week before what are likely to be far larger opposition protests to demand greater political choice.

Police said around 10,000 people gathered in Yekaterinburg, Russia's fourth-largest city, with many brought on buses and trains from outlying towns in the Urals industrial belt to back Putin before the March 4 presidential vote.

Putin enjoys strong support in many Russian regions, but faces criticism from the urban middle class, especially in Moscow and St Petersburg. Effectively excluded from mainstream politics, middle class Russians have taken to the Internet to call for sweeping electoral reform.

Tens of thousands people from different parties and others, unaffiliated to any political organization, are expected to take part in a protest march on Feb 4 to press For fair elections in Moscow, which was approved by the city's authorities.

Tens of thousands protested in Moscow and other cities in December calling for a December 4 parliamentary election to be re-run, alleging the ruling United Russia party's victory was achieved through widespread ballot fraud.

In Yekaterinburg, demonstrators held placards with slogans such as 'We are for a stable tomorrow', swayed to pop music and enjoyed free food and drink.

Buses were laid on for us at the factory, we saw lists in advance of those who would go to the rally, said Andrei Mandure, a worker at a chemical plant in the town of Lesnoy, a closed facility during the Soviet era. Putin did not attend the rally.

Public-sector workers were also out in the city's railway station square. One, a 59-year-old kindergarten worker who gave her name as Yevgeniya, told Reuters her boss had instructed her to attend.

Putin, president from 2000-08, is aiming to secure a further six-year term in March. He holds a clear lead in opinion polls, with Communist Gennady Zyuganov running a distant second.

The exclusion of liberal Grigory Yavlinsky from the slate on a technicality has further angered the opposition, which says the Kremlin has allowed billionaire Mikhail Prokhorov to run to capture protest votes without posing a threat to Putin.

There are no good candidates. Yavlinsky was banned ... (so) who else if not Putin? said Sergei, a 46-year old from Kirovgrad, when asked who he would vote for in March.

(Writing by Andrey Ostroukh; Editing by Douglas Busvine and Ben Harding)