WE were promised that the breaking of the British Gas monopoly would drive down prices.

It would appear the forces of competition have not had the desired effect.

In recent weeks, four of the new suppliers have increased their prices by between four and six per cent. And yesterday, British Gas fell in line with them, promising a 4.7 per cent rise.

Faced with the prospect of gas bills rising more than twice the rate of inflation, consumers will be hard pressed to be enamoured by the virtues of the free market.

When the suppliers appear to be playing "follow the leader" it is difficult not to arrive at the conclusion that some sort of cartel is at work.

We would hope that industry watchdog Ofgem, supposedly the guardian of consumers' interests, will check that the competition remains genuine and that the latest round of price rises are wholly justified.

The price rise, averaging £14 a year, is modest and within the reach of most households. But most low-income families remain on pre-payment schemes and are less able to shop around for cheaper deals. For them, competition has provided only scant reward.

To ensure equality for all its customers, British Gas, which retains the bulk of the pre-payment market, should consider pegging pre-payment prices.

If it refuses to do this voluntarily, then Ofgem should apply some pressure.