David Cameron has announced measures to tackle money-laundering after the UK was accused of facilitating global corruption through tax havens.
In an interview with Christian Today, a spokeswoman for Christian Aid said the "UK is enabling corruption around the world" and called on the Prime Minister to "focus on what he can actually do".
Spokeswoman Rachel Baird said: "Cameron should do what he can and start with tax havens the UK controls rather than lecturing other countries."
The first global anti-corruption summit is being held in London on Thursday. Ahead of the gathering the Prime Minister was caught on camera telling the Queen some "fantastically corrupt" countries were coming including "Nigeria and Afghanistan – possibly the two most corrupt countries in the world".
Baird said the UK was by no means the only country that facilitated corruption or even the worst but said Cameron could lead by example.
Cameron has said companies that own property in the UK will have to be declared on a new register. The government said the register would mean "corrupt individuals and countries will no longer be able to move, launder and hide illicit funds through London's property market, and will not benefit from our public funds".
Some of the British Overseas Territories and Crown Dependencies will join the register which will be available to the police. Christian Aid told Christian Today they wanted all UK-owned tax havens to sign up to the register and said it should be publicly available.
Ahead of the conference Cameron called the corruption "the cancer at the heart of so many of our problems in the world today". In an article for the Guardian he wrote: "It destroys jobs and holds back growth, costing the world economy billions of pounds every year.
"It traps the poorest in the most desperate poverty as corrupt governments around the world siphon off funds and prevent hard-working people from getting the revenues and benefits of growth that are rightfully theirs."
Ahead of the conference Christian, Muslim and Jewish faith leaders wrote to the Prime Minister and said the UK was "among the main enables of corruption". They branded it a "moral outrage", a phrase Christian Aid agreed with. The charity has campaigned against tax havens extensively and said "transparency is a big part of the answer".
Baird told Christian Today: "Transparency tends to deter corruption. It rolls back secrecy."