More than 117,000 children in the West Midlands are living in poverty despite having at least one working parent, a think tank claims.
The think tank calls for a number of reforms
The Institute for Public Policy Research (IPPR) said government efforts to tackle child poverty had "forgotten" poor parents who work.
It wants reforms such as "boosting the effectiveness of the minimum wage" and increasing the Working Tax Credit.
The government insisted "significant progress" had been made under Labour.
But the IPPR research suggested that although 600,000 children had been lifted out of poverty in the last 10 years, the number of poor children in working households in the UK remained at 1.4m.
In 1999, the government vowed to eradicate child poverty altogether by 2020.
But the IPPR said the government was failing to reward those parents who get jobs in favour of those who do not work.
Its report said the benefits system offered little incentive for a second parent to get a job.
The most widely used definition of the poverty line is 60% of median income, the mid-point on the scale of national earnings.
The IPPR report was based on the example of a couple with one child aged under 11 earning £260 per week or less before housing costs or a couple with two children aged under 11 earning £303 per week or less before housing costs.