Calls for the Commerce Commission to investigate potential restrictive trade practices and collusion by electricity generators

Entrust believes some of our biggest electricity providers are supplying Tiwai Aluminium Smelter with electricity at an artificially low-cost - at the expense of consumers.

Entrust chairman William Cairns says indications from a power company, show they're providing power to Tiwai - at the cost of operating and fuel only.

He says this means residential and New Zealand-owned businesses are missing out on cheaper, more affordable electricity - which will also be affecting job growth and lower-cost goods and services.

William Cairns says it's corporate welfare at its most cynical - stifling power competition and sending benefits straight offshore to the 100-percent foreign-owned company.