Can my ex go back on our child support agreement

Messy37

Hi
Would appreciate some help on this.
My ex and I seperated 4 years ago and never divorced. We signed a seperation agreement drawn up by both our solicitors.
Basically he pays no maintenance for me, as I earn more than him, we agreed he would pay 120 euro a week for his daughter and 50% of her medical and school fees.
There has been no issue with the payments for the last 4 years.
Recently he moved in with his girlfriend, and he has started to become erratic with payments for school stuff and medical bills. Always saying he doesnt have the money and can he pay me what he owes me next month. He never misses the 120 a week, its the other 50/50 expenses he has started to get funny about paying.
His girlfriend is not in regular work and between them I think they have debts, so I think he is subsidising her mortgage and household expenses.
The thing I am really worried about is that he is going to say he doesn't have the money to pay for our daughters secondary school fees in sept when she starts first year.
Can he do this ? Will a court allow him to channel his spare income into his lifestyle rather than pay half his daughters school fees ?
I am not asking for a lot, just for him to pay half her fees and 120 a week which goes towards her child care. I may earn more than him but I have a massive mortgage which takes 60% of my salary and I run the household on my income solely.
Help ?

FreudianSlippers

We don't do legal advice as per our forum charter. Please see a solicitor.