Around one million carers would be given an annual £250 bonus if they are looking after a sick relative, the Liberal Democrats have said.
Party leader Nick Clegg wants to double the carers allowance from £125 by the year 2020 and will make the pledge in the Lib Dem's manifesto for the 2015 election.
Mr Clegg said the extra money was a recognition of the "superhuman" work done by the "hidden army of carers".
A spokesman for the party claimed there would be a "fully costed manifesto" of the pledge, however critics of the scheme have argued the Lib Dems have not provided any details of how they would raise £280 million needed.
More top news
It will become increasingly wet and windy across parts of Scotland and Northern Ireland across the next few days.
A police helicopter went on a 40-mile search after a 999 call about a cry for help - only to discover it was a goat and her kid.
A boy from Manchester was excluded from taking part in World Book Day for dressing at Fifty Shades of Grey character.