Thousands of people will march through central London today to call for a “fundamental change” to the global financial and economic system.

The event is being organised by Put People First, an alliance of over 150 unions and development, faith and environment groups.

A statement from the GMB Union said the march would call for “decent jobs and public services for all; for justice to end global poverty and inequality and to build a green economy to stop climate change”.

Around 50,000 people are expected to attend and make their way from Victoria Embankment to Marble Arch, with a rally set to take place in Hyde Park around 14:00 GMT.

The event comes just days before disparate groups of anarchists, socialists, anti-globalisation protesters and environmentalists attempt to bring London to a standstill ahead of the G20 summit on Thursday.

The Metropolitan police have already assigned some 3,000 officers to police a mass “street party” planned for Wednesday April 1st, dubbed Financial Fools Day.

Anarchist groups will protest outside the Bank of England with some reportedly planning on attempting to break through police lines. A number of city firms have warned their staff to expect problems and have suggested dressing down so as to prevent any trouble.

Today’s marchers, however, have been keen to disassociate themselves from the more violent demonstrations.

“The event has been organised in full co-operation with the police and the Hyde Park authorities,” said Glen Tarman, chair of the organising team.

“We have no evidence that anyone attending intends to disrupt our plans, break the law or commit any acts of violence. Nor have the police informed us that they have any such intelligence.

“Put People First is not organising or collectively supporting any other demonstrations or protest events being held in the subsequent week to coincide with the G20 summit.”

Today’s protestors will also demand that world leaders take action to make sure the financial sector is never allowed to provoke such instability again, and for a low-carbon response to the crisis which focuses on poverty reduction.

The range of demands – all united under the banner of a progressive response to the downturn – reflects the variety of groups under the Put People First banner, from the TUC to the Salvation Army, Friends of the Earth to Oxfam and Shelter to War on Want.

Organisers say union delegations and poverty campaigners will be coming from around the world to the march.

“Never before has such a wide coalition come together with such a clear message for world leaders,” said TUC general secretary Brendan Barber.

“The old ideas of unregulated free markets do not work, and have brought the world’s economy to near collapse, failed to fight poverty and have done far too little to move to a low-carbon economy.”

Church leaders will also be involved in the march. The Bishop of London, Dr Richard Chartres, will join an ecumenical service at Central Hall in Westminster at 11:00 GMT, which is expected to be attended by more than 2,000 people and will then feed into the march at Westminster.

A number of high-profile figures are expected to attend the rally, including Kooks lead singer Luke Pritchard and left-wing comedian and activist Mark Thomas.