Frazer Scott, from campaigning group Energy Action Scotland, said there were growing concerns around the switch happening on time.
“With the scale of these changes over such a short period of time, we’re really concerned that it’s simply not going to happen,” he said.
“And the consequences are considerable for all those households that might be affected when it’s switched off.”
He added: “It is unacceptable that it is so late in the day with so little certainty.”
Mr Scott said it now felt as though the industry was working together to solve the issue but described it as the “eleventh hour”.
“It is incredibly worrying but at least they’ve finally got together some kind of taskforce and hopefully this will mean there will be an acceleration in this change,” he said.
He said about a quarter of the affected households were in Scotland and the country was “disproportionately affected”.
Mr Scott also called for “proper support” for people in case their heating fails.
“People just want a certainty of supply with a much cheaper cost,” he added.
“What we’re looking for from industry is certainty that people’s bills will not rise as a result of making a meter change, which would seem ridiculous.
“But at the moment we’ve not even got those kinds of assurances from industry, and nor is it clear who will pay for additional costs should a household require them to ensure they have a safe supply to their house.”
