Its research showed that pay and workplace pensions were often negatively impacted by changes to working patterns.

In particular it showed that one third of women reduce their hours for an extended period of time during their working lives, hitting their pension plans.

That could change if the government made it a legal duty for employers to inform staff of the impact that any changes in their working hours - and resultant earnings - may have on their pension contributions, the think tank said.

Its research suggested that more than half of women would like to receive more information about their workplace pension from their employer.

More regular communication that goes beyond the mandatory minimum was seen as important to increase pension engagement, according to the report.

Catherine Foot, director of Phoenix Insights, said: “Women are being left behind in their pay and pension saving at key life stages and decisive action is needed to reform current policies and practices to support businesses and individuals in addressing saving inequality.

“Alongside employers, our research with IES highlights the need for the government to increase their efforts to close the gender pension gap.”

She said efforts should be focused on improving pension policy, providing better support for employers and introducing legislative protections for women at life events.

She said: “We have identified key recommendations for these areas, including better pension accessibility and information, boosting financial literacy, and improving access to care and flexible working.

“Coordinated cross-departmental action to reform policy at the points which make the biggest impact to women’s working lives will lead to meaningful progress on the gender pension gap.”

Abbie Winton, research fellow at the Institute for Employment Studies, said: “If the current and future governments fail to act on the gender pension gap, we can be certain that increasing numbers of women will receive an income at retirement which will fail to allow them to meet their basic needs.”

The findings were contained a new report ‘Caught in A Gap: the role of government in enabling women to build better pensions’ from Phoenix Insights and IES.

The report is the second of two reports which analysed women’s long-term finances through the lens of the workplace and looked at how the life events that women may encounter affect their working patterns, choices, and consequently their ability to save.

The research was conducted by Opinium from 24 to 29 November.