Tens of thousands of trade unionists, environmental campaigners and anti-globalization activists took to the streets of London on Saturday to start five days of protests before the G20 summit. Organizers of the Put People First march for “jobs, justice and climate” have rejected as “smears” claims in police briefings that the demonstration could be hijacked by anarchists bent on violence. Chanting "tax the rich, make them pay", protesters marched through London waving banners saying "People before Profit", at the start of a week of protests that reflected growing public anger over bankers' pay and their role in the crisis. An alliance of more than 150 unions and environment, charity, faith and development groups will march through the capital from Victoria Embankment to Hyde Park to demand action to save jobs, create a low-carbon economy and impose stricter controls on the finance sector. The general secretary of the Trade Union Congress, Brendan Barber, said: “Never before has such a wide coalition come together with such a clear message for world leaders. Britain's Climate Change minister Ed Miliband met campaigners before the march got under way and said the “vast majority” were planning to protest peacefully. US Vice President Joe Biden said the protesters should "give us a chance" and listen to what politicians plan to do. "Hopefully we can make it clear to them we are going to walk away from this G20 meeting with some concrete proposals," he told reporters in Chile. World leaders, including US President Barack Obama on his first visit to Europe since he took office, will gather in London on Thursday for the Group of 20 summit. In other European cities similar protests took place with 15,000 people marching through Berlin with black-clad protestors throwing rocks and bottles at police, setting off fireworks and smashing a police car window. Up to 14,000 assembled in Frankfurt and about 6,000 demonstrators, mostly students and trade union members, marched in Rome to protest the G8 labor ministers meeting. More protests are planned in London in the days leading up to the summit. The police are most concerned about the potential for violence on Wednesday, dubbed “Financial Fools Day” by demonstrators, when an anti-war march will be held and climate change campaigners will set up a camp in the City of London financial district. Soros: Britain may need IMF bailout Meanwhile, Hungarian-born US billionaire George Soros said in an interview with the Times published Saturday it was “conceivable” that Britain would have to resort to a bailout from the International Monetary Fund (IMF). “It's conceivable,” Soros said. “You have a problem that the banking system is bigger than the economy... so for Britain to absorb it alone would really pile up the debt.” Soros said that “if the banking system continued to collapse, (an IMF bailout could be) a possibility but it's not a likelihood.” The man who made one billion dollars on selling the pound on Black Wednesday in 1992 described the current recession as a “once-in-a-lifetime event”, particularly in Britain. He said he feared the problem in Britain, with its huge financial and banking interests, could be greater than in the United States.