Single parents are being "unfairly blocked" in their careers by barriers including childcare costs and working in low-paid jobs, according to a new report.
Research by the Gingerbread charity suggested that half of children in single parent families live in poverty.
Problems faced by single parents included high childcare costs, lack of flexible jobs, and suffering from being away from work to have children, said the report.
Laura Dewar, Gingerbread's policy officer, said: "Almost all single parents are in work or want to work but our report shows many are being held back in their careers due to structural barriers which trap them in lower paid jobs.
"These blocks mean single parents are missing out on more senior roles and businesses are overlooking an untapped pool of talent.
"With some simple, practical changes the UK economy could really benefit from valuable skills and the lives of many single parent families could be improved.
"Gingerbread would like to see the Government encouraging flexible working and offering more tailored support to help single parents overcome the unfair challenges they face when it comes to career progression."
The charity called on the Government to introduce improved rights to work flexibly, and to offer single parents more childcare support.
Shadow work and pensions secretary Margaret Greenwood said: "The Conservatives have shocking disregard for the needs of children and the talents of their parents.
"They cannot be trusted to tackle poverty and inequality.
"It is wholly unacceptable that half of single parent families live in poverty and it makes no sense to leave single parents trapped on low incomes."
A Department for Work and Pensions spokesman said: "We've seen 1.3 million more parents in work since 2010, and record employment among single parents, supporting more families with a regular wage.
"We are committed to ensuring childcare is never a barrier to getting a good job.
"Through Universal Credit parents receive personalised Work Coach support to not just get into work, but also succeed in work, and can claim back up to 85% of their childcare costs."