Shadow work and pensions secretary Rachel Reeves said it was "completely unfair" that many disabled people were hit by the "bedroom tax" and charged for the space used to store essential medical equipment.
"Britain can't afford another year of David Cameron and Nick Clegg's tax on bedrooms," Ms Reeves said.
"If they won't listen to the country and scrap their hated bedroom tax, then a Labour government will," she added.
More top news
The British Army's first ever female major general said she is "very honoured" by her new role.
Nick Kyrgios risks a heavy fine after going into a sulk and appearing to stop trying during his Wimbledon fourth-round match
Serena Williams may have ended her big sister Venus' best chance for an eighth major title to keep her calendar grand slam bid on track