The problem is that if the motion is legislated and so called islamophobia is banned then media will self censor...... and will not permit any comments about Islam. for fear of crossing the line. How can this be challenged in court? I don't think it could.  So the legislation would have an insidious effect of stifling all comment and criticism about Islam. For example check the comments in today's NP by Rex Murphy.  Would the NP publish that if "islamophobia" were prohibited in legislation?   
I really hope that MPs would never be daft enough to permit such legislation to see the light of day but the Liberal party appears to have turned into flock of uncritical sheeple even though their leader couldn't even be bothered to show up for the vote on motion 103...or even the budget debate.