Ninety Christian leaders from every continent have signed an open letter to G20 leaders, urging them to take determined action on corruption and tax evasion.

The letter, which represents one billion Christians worldwide, will be presented to the G20 summit in Brisbane on 7 November.

The letter, organised by EXPOSED campaign, reminds the G20 that corruption robs US $850 billion each year from developing nations through illicit financial flows and an additional $160bn a year is lost through tax evasion.

EXPOSED, a campaign supported by the Alliance, believes this letter is the first move by such a wide constituency of the Church to take a stand on economic integrity issues.

Lord Paul Boateng, Chair of the African Biblical Leadership Initiative (ABLI) and a member of House of Lords, says African leaders want to see change: "G20 leaders cannot afford to ignore what a community of one billion Christians round the world are telling them in EXPOSED's open letter –that governments must take action on corruption, which traps millions in poverty in developing nations".

The letter has been used by national Christian leaders in the past six months as a wake-up call to their own governments. Leaders have demanded action on local issues including land-grabbing, bribery and the disappearance of millions of dollars in tendering processes and contracts. In Brazil alone, over 300 Christian leaders signed the letter.

Philippine church leader and the letter's author Bishop Efraim Tendero will hand the letter over at the summit.

He says: "Corruption is a daily part of the news here in the Philippines. In the past year it has come to light that discretionary funds in the hands of politicians, totalling $2.2m, have been diverted through bogus non-government organisations."

Rev Joel Edwards, who heads EXPOSED, says: "Good economic practices make sense for all nations and they help business to flourish if we all play by the same rules.

"If the G20 fails to act or only takes half-hearted action, then it's the poor who will suffer most - most definitely the poor in developing nations, but also the poor in Europe and Australia. Brisbane's meeting is a crucial time to see resolute action".

G20 nations, which control 85 per cent of the world's economic activity, have already begun to tackle corporate bribes, profit shifting and tax evasion.

EXPOSED urges leaders to act not only in their own interests but on behalf of small and poor communities by providing clear, open information and funding, so that developing nations can access and use data from multinationals and governments.

EXPOSED is a coalition of Christian churches and organisations that aims to challenge the global Church, business and governments to highlight the impact of corruption on the poorest of the poor.