The average income of men in Britain is almost double that of women, according to new government figures.

The latest statistics from the Department of Trade and Industry, covering the period from 1996/7 to 2003/4, show that while women are slowly narrowing the income gap - with single mothers moving fastest of all - the sexes remain far apart.

The biggest differences between male and female incomes are for those living in pensioner couples, where women's income is a mere 37% of that of comparable men.

But the gap is, predictably, smallest for single women without children, whose income stands at 93% of that for single childless men.

According to the data the median weekly total individual income for all women in 2003/4 was £161, just 53% of that for men at £303.

The pronounced gap yesterday prompted calls from equality campaign group the Fawcett Society for the government urgently to draw up a strategy on female poverty along the lines of its child poverty programme.

The report, Individual Incomes of Men and Women, examines the relative total, net and disposable incomes of men and women at different ages and in different family types.

In addition to earnings from employment, the figure includes tax credits, benefits, investments and pensions to give a rounded view of a person's income.

The Women and Equality Unit, which published the statistics, said the data could not be used as a means of comparing living standards of women and men, since a non-working woman with a high earning husband could have a very low income but a high standard of living.

The figures show that the median total income for women rose in real terms by more than twice that for men between 1996/7 and 2003/4 - a 31% increase for women compared with 13% for men.

The largest leap in total income was for single women with children, major beneficiaries under the Labour government. Their median total incomes rose by 50% over the period in real terms.

Overall, women's total weekly incomes have gone up as a proportion of men's, from 46% to 53%. The largest increase in this comparison was for women in the 25-to-34 age group, those some way up the career ladder but not necessarily with children. They saw their income rise by 15 points, from 52% of men's to 67%.

Part of the reason for the persistent income gap is down to fewer women working and the fact that they earn less.