Prime Minister Vladimir Putin gave former Kremlin chief of staff Vladislav Surkov responsibility for social policy on Wednesday, a portfolio likely to be viewed as a demotion for a man once seen as the architect of Russia's political system.

Surkov, 47, seen as the mastermind of Putin's ruling system which combines populism with top-down governance, was removed last month from the presidential administration and appointed deputy prime minister, in what was seen as a step down.

On Wednesday he was given authority over healthcare, education, housing, demographics, tourism, religion and other social issues, according to a document posted on the cabinet's website

Such social issues are often seen as being of secondary importance in Russia, where the most powerful politicians are usually in charge of security, finance or large industries.

Surkov, branded Russia's puppet master by Putin's critics, was one of the main targets of anger at demonstrations last month protesting against fraud in parliamentary elections.

His demotion was a rare sign of retreat for Putin, president from 2000-2008, who announced plans to return to the presidency this year after allowing his ally Dmitry Medvedev to serve a term. Medvedev is expected to take over as prime minister.

Medvedev has promised political reforms that will make it easier for parties to register and restore elections for regional governors, which were abolished under Putin.

Russian opposition groups say the changes are insufficient. They said on Tuesday they would hold a rally near the Kremlin on February 4, a month before the presidential vote.

(Reporting by Alexei Anishchuk)