Female executives earn £400,000 less over the course of their working lives than male colleagues with identical careers – and are far more likely to be made redundant – as they continue to suffer discrimination in the workplace.

The average woman executive earns £10,060 a year less than her male equivalent and is awarded less than half his bonus, according to research released on Wednesday by the Chartered Management Institute (CMI).

Ann Francke, the institute's chief executive, said: "A lot of businesses have been focused on getting more women on boards, but we've still got a lot to do on equal pay and equal representation in top executive roles. Twice as many female directors were made redundant compared to male directors, so at that level in the organisation it suggests that this is not all about childcare.

"It is totally counter-intuitive [to fire a woman who] has made director level. An organisation should be doing all it can to keep them there, to promote cultural diversity. We know categorically that more diversity results in better business results. It is shown in every single study. This is about good business sense."

The latest pay survey from the managers' trade body, which polled 38,843 people in executive roles in the UK, suggests that a woman and a man starting their business careers aged 25 and retiring aged 60 would take home pre-tax totals of £1,092,940 and £1,516,330 respectively, based on today's levels. Dawn Nicholson of finance firm PwC said: "The size of the lifetime earnings gap between men and women is disturbing and suggests that women are going backwards versus their male counterparts.

"If the career path is identical, then it is hard to see why the differential would exist, let alone how it could be justified.

"Employers must really ask themselves whether they are being absolutely unbiased in the pay decisions they make. They need to consider whether they are fairly evaluating the different and diverse skill sets, not just of men and women in their companies, but of all of their employees."

The research comes at a time of renewed focus on how effectively women are edging towards equality in the workplace.

Last month the Liberal Democrat equalities minister, Jo Swinson, proposed a shakeup to company annual reports that will pile pressure on firms to tackle gender imbalances. Companies will have to report how many women they employ, from boardrooms down.

Her announcement came as the European commissioner for justice and rights, Viviane Reding, renewed a push for mandatory quotas of female directors at listed companies – although her efforts have been resisted by many member states, including the UK, which prefer a voluntary code.

Opponents have been able to point towards some recent progress despite a lack of compulsion. The latest numbers from the Professional Boards Forum show that 17.3% of FTSE 100 directors are women, a rise from 12.5% when Lord Davies published his 2011 report setting a voluntary target of 25% of board seats being filled by female directors by 2015.

Even so, critics argue that the increase has mainly been attributable to the hiring of female non-executive directors, while three out of the five female FTSE 100 chief executives – Dame Marjorie Scardino at Pearson, WH Smith's Kate Swann and Anglo American's Cynthia Carroll – have recently announced their intentions to step down.

Recent analysis by the Guardian of 50 of the UK's most valuable companies showed that women account for only 14% of staff serving on executive committees – the management level one rung below the boardroom, which is seen as the pipeline of talent to fill future board vacancies.

While the CMI research illustrates the unequal level of earnings between male and female managers, junior female executives do earn marginally more than males (£21,491 compared with £21,128). However, that early edge is soon eradicated and the gender pay gap increases the higher up an organisation an individual rises, with female directors earning an average basic salary of £127,257, which is £14,689 less than the male director average.

The CMI study also shows how much more likely women are to lose their jobs. The CMI's "labour turnover data" illustrates that 4.3% of female executives were made redundant between August 2011 and August 2012, compared with 3.2% of male executives, meaning the number of women losing their jobs has almost doubled since the last survey from 2.2% in 2011.

This difference grows as women hold more senior roles: twice as many female directors as male directors were made redundant (7.4% compared with 3.1%).Labour equalities spokeswoman Kate Green said: "It is both unfair and unjustified that women should be paid less than men for doing equivalent jobs.

"The gender-pay gap at the management level is still higher now than it was in 2010, and at this rate, 42 years after the Equal Pay Act was passed, it will take at least another 21 years for management-level pay amongst men and women to be equalised. This is simply not good enough.

"It will be a continuing disappointment to many that the Government is still refusing to consider the provisions, provided for by Labour, to introduce mandatory equal pay audits if sufficient voluntary progress isn't made.

"We also learn that, in the year female unemployment hit a 25-year national high, women executives have been hit disproportionately hard by job losses and female directors have been made redundant at twice the rate of men. It is increasingly clear that, on jobs, as well as pay, the clock on women's equality is being turned back."