Labour MP Brian Donohoe said dealing with the child maintenance system has left many parents "at their wits' end", in a debate in Westminster Hall on 16 December 2009.
Mr Donohoe highlighted individual cases in his Central Ayrshire constituency, including a mother who is owed more than £44,000 in child support payments.
The MP questioned why staffing levels at the Child Support Agency were being reduced when parents are not receiving a satisfactory service.
Work and Pensions Minister Helen Goodman said the state of the public finances had to be taken into account.
"We must look for efficiencies here [at the CSA] just as we are across the public services," she said.
"But these reductions have been achieved while at the same time increasing the efficiency of the organisation."
Ms Goodman said the CSA had been given new enforcement powers, and added that the total level of complaints made against the organisation had fallen by more than half since 2004/5.