People across London, armed with torches and lights, gathered on the steps of St Paul's Cathedral last night to shine a light on corruption. The vigil marked the start of the global EXPOSED week of action, highlighting the effect of corruption on the word's poorest (14-20 October).

Taking place at one of the most famous and ancient sights of London, the event began with a performance from the London Community Gospel Choir and then speakers and Church leaders brought a message for business and government and to the Church that we all need to take action.

Suddenly the huge Cathedral door opened up and a large trillion dollar note - representing the amount that is lost every year due to bribery and corruption across the globe – emerged.

Lord Leslie Griffiths, leading churchman and member of the House of Lords, laid down the challenge facing not just government and the Church but all people of conscience: "Good and evil survive in the same place. Our job is to see that we overcome evil with good. We expose the evil for what it is and then set our targets for overcoming that evil with good.

"I believe that this campaign is part of an orchestrated effort on behalf of good-willed people around the world to see that we have the kind of world that God wants us to live in."

Bishop Pete Broadbent led the gathered in powerful prayer as lights were shone across the cathedral steps.

Each person attending received an artificial $1 trillion note and was urged to sign it and place it in the 'bank of integrity' as a way to sign the global call to end corruption petition which calls for open tax regimes and greater transparency in payments.

Christian businessman Ram Gidoomal addressed the crowd : "We need new models of ethical business…and ethical business can begin at school, as we encourage budding entrepreneurs to practise compassion and ethics."

The St Paul's vigil was one of the first of many planned around the world. The campaign aims to see 2,000 vigils take place during the EXPOSED week as hundreds of thousands of Christians stand together in prayer and action to stop corruption. These places include the White House, South Africa, Kenya, Uganda, Nigeria, Brazil, Peru, Malaysia, India, Germany, France and Australia.

The EXPOSED campaign highlights the effect global corruption has on the poor and speaks out for justice and transparency in financial dealings across the world. It is led by an international coalition of Christian organisations and aims to reach 100million people across the world, encouraging them to consider practical and positive ways to resist corruption in their communities, including their churches, and to promote increased integrity and ethics in business.Since EXPOSED was launched last year, across the world thousands of people have already become involved, some at personal risk to themselves.

To mark the week of action EXPOSED has also issued an open letter, signed by the EXPOSED steering group on behalf of 25 global partners and representing the views of millions of people across the world in 150 countries. This letter calls world leaders to include the 'poor' in discussions which curb and outlaw corruption and create fairer systems.   EXPOSED open letter, entitled 'Stop Patronising the Poor'

The petition will be in St Pauls Cathedral all week collecting more signatures, aiming to gather a million signatures and to be handed to the G20 meeting in Australia next year. The Global Call to End Corruption can be signed online at www.exposed2013.com