In what proved from the outset to be a stormy debate, Alistair Burt, a social security minister, said that the all-party social security select committee had not taken the opportunity of its recent report to suggest tearing up the Child Support Act.
Following the committee's report, the new regulations, approved by 264 votes to 46, will reduce the level of some payments and phase them in under certain circumstances.
However, a wide cross-section of MPs still believe the latest reforms are inadequate.
In a move going beyond the select committee's report, additional amounts paid by better-off parents will also be reduced from 25 per cent of income after meeting basic maintenance to 20 per cent where there are two children and 15 per cent for one child.
Sir Nicholas Bonsor, Conservative MP for Upminister, accused the agency of ignoring the plight of individuals who were suffering great hardship.
Bob Cryer, the left-wing Labour MP for Bradford South, cited so- called 'clean-break' property or money transfers reached on the understanding that no maintenance would be paid.
Rejecting calls for the agency to take these into account, Mr Burt said: 'There can be no clean break between a parent and his children. In any event, the formula already reflects the practical consequence of property settlements. 'Where an absent parent has not taken his share of any equity in the matrimonial home it is likely that he will incur higher costs when rehousing himself.
'As housing costs are taken into account pound for pound in the calculation of assessable income, his maintenance bill will be lower.'
Robert Jackson, MP for Wantage and a former Conservative minister, joined the chorus of criticism, saying: 'I appreciate that you have made changes but in my view they do not go far enough.'
Following a plea from Maria Fyfe, Labour MP for Maryhill, to MPs not to lose sight of the needs of women caring for children, Mr Burt said: 'Somebody has to make up the difference, either the parent with the child, or the rest of society.'
Mr Burt said the Government could not meet all concerns. 'I am determined that the voice which has tended to be most silent in the matter, that of the mother with care of the child, will not be the voice least regarded.'