If they are able to work, lone parents on income support whose youngest child is aged five or over will need to move from income support to Jobseeker's Allowance, where they will receive extra help to return to the workplace.
Previously, this change had been when their youngest child was aged seven.
Work and pensions minister Maria Miller said: "We know that work is the best route out of poverty, so we are determined to help more lone parents take their first steps into work. That is why, rather than being trapped on benefits, lone parents with younger children will now have additional access to the help and support they need to move closer to employment.
"Getting a good balance between work and family responsibilities is important for every parent. Jobcentre Plus advisors will actively support lone parents with things such as child care and part-time jobs, so they can get that balance right too."
Advisors at Jobcentre Plus give one-to-one advice on the range of support available, including training opportunities, childcare, help with job applications and details of part-time or family-friendly working in their area.
The Department for Work and Pensions estimates there are 1.8 million children living in households where no one works and around 600,000 lone parents relying on Income Support. The Government dedicates £6 billion per year to supporting lone parent families, but a child of an out-of-work lone parent is almost three times more likely to be in poverty than those where the lone parent works part-time and five times more likely than those working full-time.
Ministers have also announced an extra £300 million for childcare support under Universal Credit, which will help 80,000 more families work the hours they choose and, for the first time, support parents who want to work under 16 hours a week.
