The last Labour Government so hated tax cuts that it would not call its family tax credit a family tax credit. For those on the minimum wage, it could increase your income by 1/3rd. Oddly enough, because of abatement rates of 22.5% after $36,000, two minimum wage earners do not get much at all.
Some countries including New Zealand and Australia do not give ordinary families much of an incentive to earn more. Effective marginal tax rates on low income families is one of the few times that the Left discovers supply-side economics.