New research suggests single mothers would have to work an additional 28 years to retire with the same amount of money as a man.

This would take them to the age of 93, whereas a single father might only need to work an additional three years, to age 68.

The research has been done by NOW: Pensions and the Pensions Policy Institute (PPI) to mark Single Parents Day (March 21).

It found one in three single mothers are ineligible for a workplace pension under current auto-enrolment rules – which were introduced in 2012 – despite over half (59%) being in employment.

This means single mothers could have been missing out on over £852m in pension savings since 2012.

According to the research, there are over 1.59 million single mothers in the UK, and those who are eligible for workplace pensions will save an average of £885 a year into their pension – compared to the UK average of £1,573.

Samantha Gould, head of campaigns at NOW: Pensions said: “As a working single mother myself, I know all too well that the cost of childcare is a huge obstacle for single parent households. Working single parents must juggle work and caring responsibilities, meaning that they are more likely to reduce their working hours or stop working altogether.

“Through no fault of their own, too many single mothers are locked out of the auto-enrolment system, unable to earn enough to put money aside for later, so find themselves on the wrong side of a growing pension savings gap. We must ensure that everyone has an equal opportunity to save for their futures and build an adequate savings pot for later in life.”

In the UK, 54% of single mothers work part-time, compared to the UK average of 21%. As so many more single mums work part-time, they might not be eligible for auto-enrolment into their pension pots – which requires someone to earn 10,000 in a single role.

There’s the risk of pension poverty. According to NOW: Pensions and the PPI, if single mothers have a 40-year-long career with no breaks, they will retire with a private pension of £48,000 – whereas the Pensions and Lifetime Savings Association recommend £12,800 a year as the minimum.

The cost of childcare could be keeping single mums out of full-time employment or jobs that aren’t flexible. According to the Trades Union Congress, the average full-time nursery place is nearly £15,000 a year.

Victoria Benson, chief executive of single parent charity Gingerbread, said: “We already know that too many single parents are locked out of quality work and it’s devastating to see they are also likely to be locked into pension poverty.

“More needs to be done to better support single parents throughout their working lives and beyond. It’s not right that such a large section of our society will continue to experience hardship well into retirement, simply because they parent alone.”

NOW: Pensions suggested a series of measures to help single mothers and bring in “fair pensions for all”, including removal of the £10,000 auto-enrolment trigger and greater action on the availability and cost of childcare to help those who want to return to work.