David Cameron faced a furious backlash from MPs after urging Tory backbenchers not to side with "terrorist sympathisers" in opposing air strikes.
The Prime Minister was repeatedly challenged about the comments, made in a private meeting of the Tory 1922 Committee as he set out the case for military action in the House of Commons.
Mr Cameron insisted that no-one was arguing about the need to tackle terrorism and there was "honour" in voting either to back or oppose air strikes against Islamic State in Syria.
He told MPs: "I respect people have come to a different view from the Government than the one I will set out today and those who vote accordingly."
Former Labour minister Caroline Flint was the first to call on Mr Cameron to apologise for his remarks, backed up by Labour's John Woodcock who told him it would be "helpful" to "retract his inappropriate comment".
Mr Cameron said: "Everyone in this House should make up their mind on the arguments in this House and there's honour in voting for, there's honour in voting against."
Former Scottish first minister Alex Salmond also urged Mr Cameron to apologise for his "deeply insulting remarks", telling him: "You are facing an amendment signed by 110 members of this House from six different political parties.
"I've examined that list very carefully and I cannot identify a single terrorist sympathiser among that list."