One thing you could argue is that the gas/oil producers shouldn't be allowed to supply - there is always the chance that profits are shunted around the system through internal pricing and maybe finish up in the Exploration & production arm rather than the retail sales group
But then why stop with Energy........
What IS a disgrace in that neither of the main parties will force the gas suppliers to keep a reasonable amount in storage - it's only about 7 days supply in the UK whereas Germany & France have more like a month in store