MPs have warned energy companies to tighten up their disconnection procedures or face prosecution for cutting off customers' supplies.
Energy companies could face prosecution for cutting supplies
The Trade and Industry's select committee is threatening to bring in legislation banning disconnections of domestic fuel supplies.
It is concerned about vulnerable people being cut off and hundreds being left in the dark due to mistakes.
Energywatch Scotland said this was the "last chance saloon" for the industry.
The committee has outlined a range of reforms, warning that unless the energy industry demonstrates a serious commitment to solving the problems they will recommend that the UK Government legislates to ban disconnections of domestic supplies.
Energywatch Scotland welcomed the recommendations in the report, which was published on Thursday.
Chairman John Hanlon said: "This is the last chance saloon for Scotland's gas and electricity suppliers.
"The companies are now on final warning to sort the mess out. That means no more disconnections of vulnerable people and no more disconnections in error."
The watchdog believes the entire disconnection procedure fails too many consumers, from billing errors and the failure of identifying vulnerable consumers, to poor debt advice and flawed applications for disconnection warrants.
Energywatch said rocketing fuel prices were plunging thousands of consumers into debt and hundreds of thousands more into fuel poverty, forcing them to spend more than 10% of their income on fuel.
The number of disconnections in Scotland is historically much lower than in England and Wales.
However, there is concern that numbers north of the border could soar when the winter moratorium on disconnecting vulnerable people ends in March.