//Boris Johnson won’t find an extra £20 a week to support the most vulnerable in society and help parents feed their children in these difficult times.//
Why are the "vulnerable" any more badly off than anybody else. If they don't work (as many of them don't, which is among the things that makes them "vulnerable") they've lost no income because of Covid. They already get £20 pw for their first child and £13 a week for subsequent children. Why should the taxpayer (note, the taxpayer, not the Prime Minister) pay any more to help them feed their children?
As mentioned, the aircraft was due a repaint anyway. It will be used to transport the Royal Family and politicians around the world to drum up trade. The revenue from that trade will help pay the Child Benefit and other benefits that the "vulnerable" (I do love how that term is becoming increasingly popular) already receive.