I'm really sad about this. It sounds 'nice' - who wants kids to go hungry? Working at a deprived school - the thing that made children's lives miserable was parents who didn't work, who had too many kids that they didn't have the emotional capacity to nurture. This 100% incentivise people to have more kids than they actually want. We don't have enough decent sized council housing to house large families - we had families with 4 kids in 2 bed flats, the kids were miserable as the parents weren't ever bothered to take them out.
2 kids gets you an extra £7000 on UC. Higher rate tax paper needs to earn an additional £17,600 to get that... And after tax rises that becomes £20,000