The official energy price enforcer is warning consumers they face gas price increases of up to 30 per cent before winter. Ofgem issued the grave statement after it found out wholesale prices for gas next winter have already risen by almost a third. The increase could add more than £200 to the typical energy bill. Ofgem said: "We can't promise lower prices but what we can do is try and make sure that transparency is clear and make sure there's good competition in the market."