According to devolved finance rules, that move in England would trigger a significant cash boost for the Welsh Government.
The pay out could fund the support services unpaid carers need to take a desperately-needed weekly break the Lib Dems say.
More than 7,348 people in Montgomeryshire are looking after elderly, disabled or vulnerable people during the pandemic.
In a letter to the Chancellor of the Exchequer, Rishi Sunak, the Liberal Democrats have highlighted research from Carers UK showing that nationally: 64 per cent of carers have not been able to take any breaks from their caring role during the pandemic, 74 per cent feel exhausted and worn out as a result of caring and 44 per cent say they are reaching breaking point.
Welsh Liberal Democrat Leader Jane Dodds said: “Our wonderful carers deserve more support, but they are too often forgotten and ignored by people in power.
"The Chancellor must provide emergency funding now, to finally give carers a break. Their selfless dedication and commitment to their roles in the pandemic is to be admired, and I know from my own professional role as a social worker how valued they are by families."
Alison Alexander, Liberal Democrat candidate for Senedd in Montgomeryshire added: “People in Montgomeryshire looking after their loved ones are doing a remarkable and important job in very difficult circumstances.
"Montgomeryshire’s unpaid carers have taken on dramatically increased caring responsibilities during this pandemic. Most haven’t been able to take a single break since the pandemic started. Most are simply exhausted.
“The situation is doubly painful for those under the age of 18 who have to care for their loved ones as they are not given access to the Carer’s Allowance, without their parents or guardians being stripped of child benefits as a result.”