Mike Hookem has said the Prime Minister should concentrate on protecting British people against terrorists rather than telling the BBC to refer to the terror group as Islamic State.
His comments come as Cameron said Muslims would "recoil" at the name used to "justify the perversion of a great religion."
"The Prime Minister's focus should be on securing our borders from the terrorist threat - which won't be achieved by a bit of fencing - not worrying about who he may or may not upset when the atrocities committed by Islamic State are described in the media."
Mr Hookem said Mr Cameron "needs to get his head out of his sand and realise that IS is a worldwide problem rather than a regional one and needs to be recognised as one."
"We at now seeing groups such as Boko Haram in Africa and other Muslim extremist groups in the Philippines who have aligned with them."
"The threat posed must not be downplayed" he added, saying that it was "straight forward common sense" that defence spending was ring fenced at 2% of GDP and more border guards were sent to Calais.