Single mothers will be hit harder than any other group by the coalition Government's programme of benefit cuts and tax rises, losing an average 8.5% of their income after tax by 2015, according to a report.
Cuts to public services will also hit lone parents harder than other households, costing them the equivalent of 18.5% of their net income - more than double the impact on couples with children.
Gender equality charity the Fawcett Society said that the Government was expecting some of the least well-off to act as "shock absorbers" for the rest of society by taking the brunt of the cuts.
The society's report - entitled Single Mothers: Singled Out - draws on analysis by the Institute for Fiscal Studies of the impact of changes announced in George Osborne's emergency Budget in June 2010, last autumn's Comprehensive Spending Review and the March Budget.
It found that by 2015 the average single mother will have lost the equivalent of more than one month's income a year due to changes including reductions on housing benefit, the restriction of maternity grants to the first child, a three-year freeze on child benefit and a cut in the childcare element of the working tax credit.
Lone mothers will lose around 8.5% of their net income, compared with 7.5% for single fathers, 6.5% for couples with children, and about 2.5% for couples without children, the report stated.
Fawcett's acting chief executive Anna Bird said: "Women are bearing the brunt of cuts. Single women, on average, are set to lose a greater proportion of their income than other households, such as single men or couple households. In part this is because women are typically poorer than men, but it is also because women make up the vast majority of lone parents - and it is this group that is set to lose most under the reforms. Some of the least well-off in our society are being forced to act as shock absorbers for the cuts, with women - in particular single mothers - faring worse."
A Treasury spokesman said: "Cutting the deficit and getting the economy going again is good for everyone. This has meant tough decisions, but the Government has made these in the fairest way, taking real action to benefit women in all aspects of their lives.
"Child tax credits have been increased for the poorest families and action taken at the June Budget will help lone parents into work, estimated to increase the numbers in employment by up to 25,000. What's more, 260,000 women will be taken out of tax by the Government's increase in the income tax personal allowance."
The chief executive of single parents' charity Gingerbread, Fiona Weir, said: "Last weekend the Prime Minister described single mothers as heroic but today's findings give his words a very hollow ring. The Government talks a lot about promoting responsibility and backing aspiration, but on the ground these cuts are actually stopping single parents from getting on. It is unacceptable that single parents are bearing the brunt of cuts and this research proves again that the Government must do more to support single parents, including further investment in childcare, training and employment support."