paying back legal aid

Just wondering what the situation is with regards my ex paying legal aid bill. During the process he had stated that he was going to use the money for a deposit on a house for himself (and if i remember correctly there was something in the court order about legal aid), however he was on incapacity at the time and still is and will be for a while, and even if he did work again i think it unlikely he would get a mortgage for various reasons. His solicitors continually stated the money was for this purpose. I am aware that he could have had a charge placed on the property if he used the money he recieves, but what will happen when he has no intention or chance of buying his own property, will his solicitors put in a claim immediately or will they wait the six months.