Labour would look at ending the household benefit cap but has not costed the measure, according to the shadow work and pensions secretary.
Debbie Abrahams said the party would consider removing the cap which limits welfare payments for households to £20,000 outside London and £23,000 inside the capital.
She told BBC 1's Andrew Marr Show said: "We recognise that for some people listening to this that might seem like an awful lot of money but the reality is, what I've just said, the implications for people in the poorest circumstances, the implications around child poverty which affects children not just while they're young but for the rest their lives - it affects how their brains develop and everything."
Pressed on whether the cap would go, Ms Abrahams said: "We would be looking to see how we do that."
She said the party had not costed the measure yet, but added: "We know that, for example, the court ruling is about £50 million so it's not an astronomical figure."
On Thursday, the High Court declared the Government's benefits cap unlawfully discriminates against lone parents with children under two.
Mr Justice Collins ruled in favour of four lone parent families in their action against the Work and Pensions Secretary over the benefit cap, which limits the income households receive in certain benefits.
The judge announced that the regulations are "unlawful insofar as they apply to lone parents with a child or children under the age of two", as they involve "unjustified discrimination" against parents and children.
The Department for Work and Pensions intends to appeal against the decision.
Ms Abrahams said Labour would "make sure that we were upholding the ruling from the court decision".
A Department for Work and Pensions spokeswoman said: "The benefit cap incentivises work, even if it's part-time, as anyone eligible for working tax credits or the equivalent under Universal Credit, is exempt.
"Even with the cap, lone parents can still receive benefits up to the equivalent salary of £25,000, or £29,000 in London, and we have made Discretionary Housing Payments available to people who need extra help."