The world's banks need serious reform, veteran American civil rights activist Jesse Jackson told hundreds of protesters gathered in the centre of London as part of the Occupy protest on Thursday.

In the latest in a series of events to support the Occupy movement, which has set up camps in city centres in many Western countries, the 70-year-old Baptist minister spoke passionately to around 200 protesters outside St. Pauls Cathedral on poverty, capitalism and homelessness.

“We need a new bank policy, we have lost checks and balances in the system,” Jackson told Reuters.

“People don't feel right about banks getting bailed out and bankers getting bonuses while there are high levels of unemployment,” he added.

“The Occupy cause is a moral cause, a global spirit. It's a just cause and they shouldn't be dismissed but heard,” he added.

“There is Occupy in New York, Chicago and around America. But the spirit of Occupy is to address inequality, income gaps, concentrated wealth and poverty around the world.”

Jackson sought the Democratic presidential nomination for U.S. president in 1984 and again in 1988, running on a liberal platform.

He was an aide to Martin Luther King during the American civil rights movement and played a leading role in the civil rights movement in the 1960s.

The group has been camping on the steps of London landmark St Paul's Cathedral since October, defying the onset of winter.

The protest caused ripples in the church, after a row of high-profile resignations within the church over how the protest was handled. - Reuters