Moscow prepares for mass protest against Putin The opposition blogger Alexei Navalny, who has been summoned for questioning by police at 11am, meaning he will miss the start of the protest. Photograph: Mikhail Voskresensky/Reuters Moscow is bracing itself for a mass anti-Putin protest on Tuesday that will be a key test of whether a Kremlin campaign of intimidation in recent months has succeeded in cowing the country's nascent opposition movement. Tensions have been rising in the Russian capital before the demonstration, which has a licence for 50,000 attendees, after police searched the homes of prominent activists and their families on Monday. Opposition figureheads including the blogger Aleksei Navalny, Left Front leader Sergei Udaltsov and TV star Ksenia Sobchak were targeted by police and have also been summoned for questioning at 11am local time, meaning they are likely to miss the first hours of the rally. The searches - and a controversial new law regulating protests - are widely considered to be an attempt by the authorities to fracture Russia's opposition, which became a force to be reckoned with after widespread fraud allegations during December parliamentary elections pushed people on to the streets in numbers not seen since the fall of the Soviet Union. While more than a dozen mass demonstrations during the winter and spring months have produced few obvious results, there is little sign the movement's momentum is waning. Beginning on Pushkin Square, Tuesday's march through central Moscow starts at midday before culminating in a rally due to end by 6pm. A demonstration is also planned in Saint Petersburg. It will be the first opposition event since the president, Vladimir Putin, signed off on a new law that dramatically raises fines for individual protesters and organisers of unsanctioned demonstrations. The legislation was hurried through Russia's parliament after the last big opposition protest on 6 May descended into a bloody melee with activists hurling rocks at riot police and more than 400 arrests. About 70,000 police officers will be on duty across the country on Tuesday, which is also a national holiday to mark the moment the Russian Federation was born in 1990. Extra riot police have been brought into the capital. Clear blue skies and temperatures of over 20C in Moscow await demonstrators, who identify themselves with white ribbons, although thunder storms are forecast for the late afternoon.