The average woman expects to retire with income of £12,250 a year compared to £18,000 for the average man.

The firm questioned almost 10,000 people aged over 45 including 1,000 who were planning to retire in 2012.

Nearly half of women said they were not confident they would have enough money for a comfortable retirement.

The gap is not helped by the fact the average amount of pension that men and women expect to receive has fallen to a five-year low of £15,500 including private, state and company pensions, down from £16,600 last year.

The difference was most significant in the South East and Scotland which both had a gender gap of over £7,000. Women in the South East expected to retire on £12,259 while men expected to retire on £20,137. In Scotland, women expected to retire on £10,029 while men expected to retire on £17,539.

It was least significant in the North West and North East which both had a gender gap less than £3,000.

However, the gap has got narrower since 2010 when the average gap between genders was highest at £7,400.

Stan Russell, Prudential’s retirement income expert, said: “The pension gender gap appears to be narrowing, but there is still a long way to go.

“The practical steps that women can take to improve their retirement income prospects include maintaining pension contributions during career breaks and, if possible, making voluntary National Insurance contributions after returning to work.”