It depends on the voting power the council had at the meeting of creditors. It is sometimes possible to sway the vote by getting more creditors to vote 'yes', especially if some simply didn't vote. If this is a possibility your IP should have adjourned the meeting and be canavassing for votes. Usually council tax debts do not have such a sway, being, often, smaller debts compared to others.
My opinions are merely that .. opinions based on experience. Always seek professional advice.
IVA Completed 23rd July 2013 .... C.C. 10th January 2014