The Church of England has accused the Government of appearing to have no "coherent or comprehensive approach" to tackling the rise of Islamic extremism.
The Bishop of Leeds said "many" senior clergy were seriously concerned by the UK's strategy in a strong attack on David Cameron's handling of the crisis in Iraq.
The Right Rev Nicholas Baines has written to the Prime Minister criticising a "growing silence" over the fate of persecuted Christians who have fled militants in Iraq.
"Please can you tell me what is the overall strategy that holds together the UK Government's response to both the humanitarian situation and what IS is actually doing in Syria and Iraq?" he wrote on his website.
"Behind this question is the serious concern that we do not seem to have a coherent or comprehensive approach to Islamist extremism as it is developing across the globe."