Why won't Labour end child poverty at this election?

Labour is saying it cannot afford to end child poverty. That, however, is only because it is refusing to charge more tax on the wealthy. Worse, it is refusing to acknowledge that this is the choice that it is making. For example, if it simply equalised the tax rates on income and capital gains, it could raise the money needed to end child poverty six times over. No reasonable person could object to that. So why is Labour refusing to consider it?