I separated from exP about 5 months ago and we are stil arguing (through solicitors) about maintenance payments.
We have reached a figure that we agree on and my solictor sent his a letter asking that the payments be index linked. I had assumed this was a formality and he would say yes but he's said no. Apparently he's been very generous as it is and can't afford to pay any more. 
I will be asking my solicitor to go back and push the issue but I was just wondering if it is the usual thing to do this, or if we're asking for something unusual? I'm just concerned that if I don't get this secured now, either I'll never get any increase to maintenance or we'll have to fight through solicitors each time it needs to be increased. And I'm sure it will need to be increased. DS is nearly 5 - it can't stay at the same level for the next 13 years!