Fund schools and social services properly.
Education is the best way out of poverty.
School was my saviour. My parents were violent alcoholic drug addicts. My school at the time was a warm, safe environment.
My teachers were not at breaking point so noticed what was going on. Had the time to understand what was going on and to help me while the balls were rolling with social services for me to be removed. They made sure I was fed on the days I wasn't fed, they made sure I could wash my hands and face on the days I wasn't allowed to use the bathroom, they recorded everyone to help the case to have me away and they made sure I learned so I could escape repeating the cycle by getting a good job.
Schools now spend so much time firefighting, and have had staff cut to the bone, that children like I was don't get the same level support. And that is in no way a criticism of the school staff - my teacher had a class helper she could call on when needed, our school nurture teacher was around, the school librarian was lovely, and the HT and DHT were in and out of classes often. Teachers now just don't have that level of support - and classes are often bigger on top.
Social services are vastly underfunded and therefore cannot help the children they should be helping, only able to be involved in the very worst of cases.
The other big change that would help child poverty, and child outcomes generally, would be to change societal attitudes over dodging maintenance and/or walking away from your children altogether. It's socially acceptable to not pay your ex for your child, all you have to do is claim she'll spend it on her hair or her night out. And it's so common that people don't pay anything when someone who pays £100 should pay £400 it's seen as greedy by the RP to push for more because "I don't get anything". The whole attitude to it needs to change.