Labour MP Diane Abbott said the government will fail to achieve its goal of eradicating child poverty in the UK unless it concentrates first on London.
The Hackney North and Stoke Newington MP cited figures from charity Save the Children, which show that London is home to around one fifth of all children in severe poverty in the UK - more than 300,000 children - the biggest proportion of any UK city.
Ms Abbott said in a debate in Westminster Hall that, without a focus on London, it would be "numerically impossible" to reduce and eventually eliminate child poverty in the UK as a whole.
The MP highlighted a lack of part time jobs in the capital and the high number of single parent families living in severe poverty, and raised concerns over the impact of impending cuts in public spending.
Ms Abbott, who pointed out that the public sector is the largest employer in Hackney, said: "One man's public expenditure cut is another woman's job loss."
Work and Pensions Minister Helen Goodman said Save the Children's figures dated from 2007, and that measures put in place since then had further reduced the number of children living in poverty.
She said the London Child Poverty Delivery Group was working to promote part time working in the city and increase the take up of tax credits.