How to take Ex to court for school fees

Hi.
I split with my daughters' father nearly 10 years ago. He pays monthly maintenance via a private arrangement which has not changed in 8 years - slightly below CSA levels now.
I lost my job 18 months ago and would like him to contribute towards our daughters' school fees - she was in private school when we split and I have continued to pay her fees from my own salary.
He has 2 other children, both of whom are in private school.
How do I go about taking him to court to try to get a top up payment to cover all or part of the fees? He earns >>£100k plus bonus and has done for years.
I'd like to avoid using solicitors if possible, as they are hugely expensive & I'm not currently working.
Thanks

I'm not sure you would be able to if its not listed in your Consent Order. Separation of assets in Ancillary Relief is usually weighted in favour of the parent with care and this ought to have been taken into consideration at the time of separation.
With regards to the money you receive from your ex, if he is paying below CSA levels then you can apply directly to them for an assessment. But this is not pleasant, we have just been subjected to this by my fiancé's ex and it is very intrusive, so maybe you could speak to your ex first and explain the situation. If you are hoping to be back in work soon then you could be looking at a short term solution. Applying to the CSA may cause a lot of resentment that you will find it hard to overcome in future, particularly if he was paying above CSA levels for a long time.

Thanks - however, we were not married, so there is no consent order. I have avoided the CSA as I don't think they benefit anyone.
I have tried to explain the situation - he's not interested. Although the school are sympathetic, they cannot award a bursary as he earns too much, therefore I'm in a bit of a nightmare situation.
My only option is to take him to court - I'd appreciate some guidance as to how to start the process myself.

Court is not an option here, the only agency that you could deal with would be the CSA.

If he's earning £100K and paying slightly less than csa rates it still must be a large amount.

Now your not working you should be entitled to housing benefit, income support, child tax creds and benefit. None of this will be effected by your ex's maintenace contribution - perhaps the money could be used for the school fees?

Under Schedule 1 Children's Act 1989 the court has the jurisdiction to make an order for a lump sum or periodic payments to meet some or all of the expenses incurred in connection with the provision of school fees. Also the court can order child maintenance top up payments if the non resident parent's income exceeds the CSA/CMEC capped amount of £2k per week.

Among the established principles for determining Schedule 1 applications are parents’ financial responsibility exists regardless of the commitment in the relationship; the focus should be on the child’s needs or welfare; provision is for the child, not for the parent with care; there should be proportionality between parents; and the established standards of living may have an impact.

The application form for Children Act applications is C1 which is available from HM Court Services website. However, Schedule 1 applications can be a minefield and it is advisable to first consult a lawyer to find out where you stand and what options there are given the particular circumstances even if you then decide to self represent afterwards.

That's fantastic. Thanks so much for your help.
I will try the forms myself and see if the local Citizens Advice Bureau can help me navigate the process.
Many thanks to all on the forum - fast and excellent advice.