A single mother in the lowest disposable income group can expect to lose one of every four dollars lost by that group in the budget's aftermath come 2017. Women in middle-income households will suffer much more than high-income women. The analysis comes as Prime Minister Tony Abbott released a video on the weekend in which he said one of his government's main motivations in future will be "protecting the vulnerable." The new slogan marked a deliberate and noticeable change of rhetoric from Mr Abbott's previous public messages, and follows months of criticism that he and his Treasurer, Joe Hockey, have endured for their budget's likely negative impact on poor households. An opinion poll published this week also showed Mr Hockey has recently become the least popular member of the Coalition front bench, falling from third place nine months ago when a similar poll was taken.

The new analysis, conducted by the Australia Institute, shows women in the poorest 20 per cent of households will be $2566 worse off in 2017 as a result of the budget. Women in the wealthiest 20 per cent of households will be only $77 worse off on average in 2017. The analysis accounts for disposable income after tax, including welfare payments, and considers the impact of the government's controversial fuel indexation changes, fringe benefits tax changes, and the loss of the low-income super contribution from July 1, 2017. The analysis does not include the likely impact of the proposed GP co-payment and higher education measures. Marie Coleman, chairwoman of the National Foundation of Australian Women and former head of the Social Welfare Commission, called the figures "alarming."

"Whether it was intentional or not this is a shocking budget for low-income women and for women generally," Ms Coleman said. Opposition Leader Bill Shorten said the impact of budget was "unfair" but it was "even worse for Australian women." "This says everything about how unfair this budget is," Mr Shorten said. "It is astonishing that a mother earning less than $30,000 will lose more from this budget than some high-flying chief executive." A senior economist at the Australia Institute, Matt Grudnoff, said women are, on average, poorer than men in Australia, and the analysis showed the budget would not help matters.

"This budget is reducing gender equality even more. If you look at the pay gap between men and women, it's an issue that's getting worse, not better," Mr Grudnoff said. Recent figures from Bureau of Statistics show the pay gap between men and women in Australia had widened to 18.2 per cent, up from 17.1 per cent at the start of the year. Between November 2013 and May 2014, Australian men's salaries increased an average $24.90 per week and women's increased only $7.09. Average cost of budget measures per adult

Poorest fifth of households: $1,847.57 (males) $2566.73 (females) Second poorest fifth: $664.40 (males) $866.54 (females) Middle fifth of households: $1311.49 (males) $1376.70 (females) Second richest fifth: $1691.50 (males) $1618.86 (females) Richest fifth of households: $78.83 (males) $76.02 (females)

Source: NATSEM Loading Twitter: @grhutchens