The posters are being paid for by Islamic Relief, an international humanitarian organisation founded in Birmingham in 1984. The ads display the slogan 'Subhan Allah', meaning 'God is Great' or 'Glory to God', and will start appearing on buses in five UK cities this Friday.
Elements of the media have criticised the campaign, pointing out that cinemas recently refused to screen a Church of England advert containing the Lord's Prayer.
But Islamic Relief spokesperson Martin Cottingham suggested that this was not a fair comparison, and that the Islamic Relief ads were more similar to fundraising campaigns that Christian charities such as Christian Aid or Tearfund regularly carry out without controversy.
He told The Independent: "It's important to emphasise that Islamic Relief is not a proselytising organisation. We are inspired by faith, but our money goes to people in need – people of all faiths, and of none.
"A lot of Christian charities have fundraising campaigns around Christmas, as it's a time when people give generously. Ramadan is very much in parallel with that. It's a time when Muslim charities would want to appeal to their community."
"I am a Christian, and I've worked here for five years. When the Lord's Prayer controversy was rife, not one of my Muslim colleagues were offended by that campaign. They thought it was a shame that it didn’t get an audience, and I would hope that people would be open-minded about this campaign in the same way."
The campaign is being represented in the media as a fundraiser for victims of the Syrian Civil War, but Mr Cottingham explained this was also inaccurate.
"The media coverage has focused a lot on Syria, but we work in 33 countries around the world. We have had a constant appeal for Syria running throughout the conflict, and our appeal in Ramadan is more about the entirety of our work.
"The bus campaign is part of a wider appeal, which will use videos, posters and leaflets to focus on our projects in Bangladesh, Kenya, Syria and Gaza. Our annual Ramadan appeal generates between a third and a half of our annual income.
"It's also an opportunity to get across the meaning of Ramadan, as a time of spiritual reflection when Muslims give to those less fortunate than themselves, but it's a charity fundraising campaign first and foremost."
British Muslims donate more than £100 million to charity during Ramadan each year, while Islamic Relief’s Ramadan Appeal raises up to £20 million annually.
The Advertising Standards Agency says it has not received any complaints about the campaign.
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