The rulings will be the latest in a series of arguments between the new gas suppliers and British Gas over advertisements by the new companies claiming their gas is up to 30 per cent cheaper. There is also a complaint pending about Swalec, the South Wales energy company.
According to a spokesman for the ASA, the two new cases reached the publicity watchdog because they did not compare like figures with like. The spokesman said: "Comparisons were made between British Gas's standard tariff and a reduced tariff by the independent companies for customers who pay by direct debit.
Last year the ASA found against two other independent gas companies, Calortex and Eastern Natural Gas, for similar misleading advertisements.
"What we are seeing are teething pains because it is a new market. Hopefully, they won't make the same mistake again," said an ASA spokesman. The market in gas was opened up to free competition in this country two years ago.
Mike Brindle, marketing manager of ENERGi, admitted that the ASA had been investigating a complaint against the company. "We've made it clear in all our new literature exactly what we are comparing prices against."
British Gas last week welcomed a new advertising campaign by Calortex, which offered savings of 21 per cent for direct debit customers compared with a 15 per cent discount being offered by British Gas because "it showed the true level of savings", according to a spokesman.
Meanwhile, Sir Harry Secombe has been unwittingly dragged into an argument following complaints over an advertisement by the Midlands Electricity Board (MEB).
Sir Harry did the voice-over for the television advertisement which claimed a 30 per cent discount on gas prices, compared with those offered by British Gas.
MEB claimed 30 per cent discount at 500 kilowatt hours, an amount which is too small to make any comparisons, according to British Gas and Geoffrey Williams, an independent gas consultant who has lodged complaints with the Independent Television Commission and the gas industry watchdog Ofgas.
"What Sir Harry did was in total, 100 per cent good faith. Obviously, if there is something untoward we will have to look at it again," said his public relations manager.