Some 10,000 protestors have gathered in London to stage a series of demonstrations before and during the April 2 G-20 summit to be attended by world leaders, including Prime Minister Manmohan Singh, as London Police prepare to combat the 'unprecedented' security challenge.
The first of such demonstrations will be held on Saturday. It has been organised by an alliance of more than 150 unions, environment and faith groups under an umbrella calling itself Put People First.
The organisation says: "Our future depends on creating an economy based on fair distribution of wealth, decent jobs for all and a low-carbon future. There can be no going back to business as usual."
On Saturday, the protesters will march four miles from the Victoria Embankment to Speaker's Corner in Hyde Park on a route past the Houses of Parliament, up Whitehall and along Piccadilly, and then culminate in a rally in Hyde Park.
Trades Union Congress general secretary Brendan Barber said: "Never before has such a wide coalition come together with such a clear message for world leaders."
It is the largest gathering in the capital since the Stop the War march against the 2003 invasion of Iraq. The Metropolitan police have described as 'unprecedented' the threat to London from the protests, and leave of thousands of policemen has been cancelled.
A series of protests are planned throughout the coming week. Protesting groups include the Campaign Against Climate Change, 20 Meltdown, Rising Tide and the Stop the War Coalition.
Security at the headquarters of banks, insurance companies, hedge funds and other financial institutions has been tightened and meetings with clients postponed. Some organisations are closing altogether.
There are fears that banks and other financial institutions could be the focus for violent protests.
Commander Simon O'Brien of the Metropolitan police said: "It's fair to say that this is one of the largest, one of the most challenging and one of the most complicated operations we have delivered.
"G-20 is attracting a significant amount of interest from protest groups. There is an almost unprecedented level of activity going on. The unprecedented nature is about the complexity and scale of the operations over a number of days."