At the launch of the Cambridgeshire Childcare Links project yesterday, Ms Harman said:
'Ordinary families in East Anglia are having to pay thousands of pounds of their hard earned money in taxes to pay for this government's failure on the welfare state.
'The cost to the public purse is up. And life for those on benefit is harder. The Tories are hitting the taxpayer and hitting the poor.
'1 in 5 households of people of working age now have no-one in work. Many of these are households headed by lone mothers.
'The number of lone mothers in East Anglia is growing and has reached 50,000. They are among the poorest people in Britain. Almost half of all lone mothers and their children have to live on less than£100 a week, compared to only 4% of married couples.
'The reason why lone mothers are amongst some of the poorest people in Britain today is because they are trapped on benefit and not in work. 59% of lone mothers in East Anglia are not working.
'Married women are increasingly going out to work, but lone mothers are falling out of the labour market. The proportion of married mothers in employment has increased since 1979, but the proportion of lone mothers in employment has fallen.
'Lone mothers want to work. They do not want to depend on benefit. But the government's policy for the past 17 years has been 'Here's your order book, come back when your youngest child is 16.'
'And it is the taxpayer who has to pick up the bill. The benefit bill for lone mothers in East Anglia is£222m a year and growing.
'We need to get lone mothers into work, as happens in the rest of Europe. In France, 82% of lone mothers are in work and only 33% are dependent on benefit. But in Britain, only 41% of lone mothers are in work. So over 70% are dependent on benefit.
'The government says their cuts in benefits to lone mothers are part of the Tories approach to being fairer to families.
'But the cuts in benefits to lone mothers will not cut the divorce rate or keep one family together - they will simply make hundreds of thousands of the poorest children worse off.
'Instead of shaving off benefits year by year and making life for lone mothers and their children even harder, there should be an active strategy to help lone mothers off benefit and into work.
'I particularly welcome the development of 'One Stop Shop' projects like the Childcare Links project here in Cambridgeshire.
'Many women who want to move off benefit and into work find that it is difficult to make sense of the mountain of disparate information on job opportunities, the cost of childcare, the availability of training, and entitlement to benefits.
'Projects like Childcare Links will provide an invaluable source of help for lone mothers who want to work by bringing together all the relevant information in one place.'
Ms Harman also outlined Labour's proposals to help get lone mothers off benefit and into work.
She said: 'Labour will:
-- invite lone mothers, when their youngest child is in the second term of full time school, to come to the Job Centre where lone mothers will get help with job search and advice on training opportunities and child care
-- develop a National Childcare Strategy including a network of after school clubs
-- provide a flexible and personalised benefits service through our network of One Stop Shops
-- make lone mothers a priority for receiving financial support towards the opening of Labour's proposed Individual Learning Accounts
-- set targets for Training and Enterprise Councils for the number of out of work lone mothers receiving training and entering employment
-- publish regular statistics about the number of lone mothers dependent moving off benefit and into work to monitor our progress.'