Adam Scorer, energywatch's director of campaigns, also said the report highlighted the need for more consistent social tariffs in the UK.
He explained: "With winter on the way and government about to announce a rise in fuel poverty, we need to look at the best that suppliers have come up with and use that to push the laggards in the industry to do more.
"The gap between the good, the credible and the token is too great to be able to rely on the diversity of supplier provision."
energywatch's latest criticism of Ofgem follows the watchdog's praise for EU plans to "unbundle" major energy suppliers in an effort to increase competition in the gas and electricity market.
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