The Government has been told to stop penalising single parents who work outside the home.
Campaign group SPARK said a failure to provide affordable childcare was preventing parents from holding down a job.
They also claim those who do work are hit with social welfare cuts.
Exchequer figures released on Friday show tax revenues are 5.8% ahead of target in the first nine months of the year.
Figures for the first nine months of the year show almost all the major tax areas are ahead of schedule, with a huge surge in corporation tax. SPARK want some of that money used to help single parents.
Government spending meanwhile is around 1.3% below projections
SPARK spokeswoman, Louise Bayliss said recent cuts had hit working lone parents especially hard.
"These reforms have pushed lone parents out of work," she said. "A lot of people were forced to work more hours, getting more money in theory but then losing rent allowance (and) supplements. A lot of people have been forced to give up their jobs to go on social welfare.
"The only people who were penalised were working lone parents. Lone parents who weren't working lost nothing."