Christian Voice charged a recent episode of the drama that focused on evangelical extremists killing Muslims could be seen as a biased view of Catholics across the world, The Daily Mail reported.
"Most people watching it will just spot another bit of BBC bias and inaccuracy -- nevertheless it shows a worrying mind-set in the people that are producing the program to even think that there are Christians contemplating violence against any Muslims whatsoever -- it is just not what we do," said Christian Voice head Stephen Green.
The controversial episode, which also showed a bishop setting up the assassination of an outspoken Islamic preacher, drew the wrath of the Evangelical Alliance as well.
"I do think that there is a sinister and malicious agenda at work here and that they are trying to plant the seed of the idea through fiction that evangelical Christians are just as likely to carry out terrorism as some members of the Islamic faith," said Don Horrocks, the group's public affairs director.
The BBC denied both groups' claims and said its programming is oriented towards Britain's diverse population.