The Moscow authorities have authorised a protest by the Russian opposition on February 4 which will pose a new challenge to Vladimir Putin a month ahead of presidential polls, officials said today.

The city hall has sanctioned the protest march south of the Moscow river with up yo 50,000 people set to gather from midday to 3:00 pm local time (0800 to 1100 GMT), deputy Moscow mayor Alexander Gorbenko told the Interfax news agency.

"The city hall has agreed to one of the variants put forward (by the opposition) that is acceptable to both sides," he said.

Last month mass protests took place, on December 10 and December 24, against the conduct of parliamentary elections, bringing tens of thousands of people out on the streets and displaying the growing discontent with Putin's rule.

Next month's protest will see demonstrators march from Bolshaya Yakimanka street in the south of central Moscow to Bolotnaya Square just opposite the Kremlin walls on the other side of the river.

It will come take place a month ahead of the March 4 presidential election in which Putin is standing for a third Kremlin term after his four-year stint as prime minister, in defiance of opposition complaints that he has been in power too long.

One of the organisers of the upcoming protest march, journalist Sergei Parkhomenko, described the arrangements as a "compromise" acceptable to both the opposition and the city authorities.

He told Interfax that the date of the protest was "symbolic" as it would also mark two months since the December 4 parliamentary elections that sparked the mass rallies that have smashed the taboo against protests in Putin's Russia.