Millions of low-income households face a steep rise in their council tax bills because of benefit changes that will take effect from April.
Researchers have warned that a variation in rates of council tax support could undermine the Government's new universal credit, which is meant to simplify the welfare system and ensure it always makes financial sense to take a job.
The axeing of council tax benefit has major implications for universal credit, which is supposed to be all about simplifying welfare and giving people a stronger incentive to work.
"These changes undermine both goals. There will now be a highly-complex and confusing patchwork of local support while the low-paid will keep even less of an extra pound in earnings than the Government has claimed."
More top news
Jeremy Hunt could impose controversial new contracts for junior doctors by Monday, ITV News Political Editor Robert Peston has learned.
A new video has emerged online purporting to show a four-year-old British boy blowing up a car and killing three prisoners on behalf of IS.
An inquest has heard Charlie Jermyn died just 30 hours after he was born because he was not given the right antibiotics.