Councillors said they want more time to consider the project and revisit the site. Planning officers have given a positive recommendation. A committee will decide whether to back the plan before it goes to government.
Director of regeneration and development Robin Cooper said: "This is one of the largest planning applications that the council has ever handled. It is right that members are given the opportunity to understand all the issues."
One of the main objectors, Greenpeace, claimed that the plant would only be 45 per cent efficient. But an E.ON spokeswoman said the firm is looking at the possibility of a district heat and power scheme to improve efficiency.