Neville Nagler, director-general of the Board of Deputies of British Jews, accused the aid agency of "supporting propaganda" by exhibiting paintings by artist John Keane "with a distinctly pro-Palestinian voice".
Keane was the official British artist during the Gulf war in 1990 and recently toured Israel and the occupied Palestinian territories with Christian Aid staff.
The resulting exhibition, 'The Inconvenience of History', opened at the London Institute Gallery to rapturous acclaim by former minister Mo Mowlam and comedians Harry Enfield and Jeremy Hardy. But the Board of Deputies took a different view.
"Christian Aid's support for a propaganda display of this kind is hardly consistent with its claim to ensure that its publications are balanced," wrote Nagler in a letter to Christian Aid chairman Bishop John Gladwin.
Nagler expressed "dismay" at the pro-Palestinian themes of the exhibition images that were displayed on the Christian Aid website.
"I would be interested to know if Mr Keane produced other, more balanced works, and if you have any intention of displaying the tragic aftermath of terror attacks," he added.
Christian Aid, which paid £8,000 to sponsor the exhibition and receives a percentage of proceeds from each painting sold, says the paintings will be shown until the scheduled end date of March 11.
Daleep Mukarji, director of Christian Aid, said: "We want to be balanced but it's impossible to satisfy everyone."
Mukarji claimed the exhibition was about poverty rather than political statements. "Because of our humanitarian agenda we need to tell the story of why there is poverty, and in this case the poverty is worse among the Palestinian communities," he said.
"There is no point just giving relief. You can't be in firefighting situations without looking at the reasons for that fire. Sometimes the Board do appear to be sensitive, but when you look at the situation in Palestine, that is understandable," he said.
Keane admits to Palestinian sympathies but denies the exhibition is anti-Israeli. "The exhibition is the culmination of 18 months of work and I am thrilled to see it all come together," he said.
Mowlam described the pictures as "amazing". "They tell the story of Palestine well; they show the state of the country and the mind of the people," she said.
Jeremy Hardy added: "I think it's really important that NGOs have become so cutting-edge."