E.ON has called on energy ministers not to make too many changes to the Energy Company Obligation, a program that enforces a green levy on energy suppliers.
Under the program suppliers are also obliged to install energy efficiency measures in the homes of consumers by March 2015.
However, ministers are now planning a reform.
The stance taken by E.ON contrasts to that taken by many of its rivals, who have stated that they'd cut their energy prices "within weeks" if the green levies are reduced.
Tony Cocker, E.ON's chief executive, has stated: "Let's not tinker with ECO too early; you don't change the rules half-way through the game."
Energy efficiency director at the big six energy supplier, Don Leiper, echoed similarly said: "ECO is effectively a legal obligation, which we are almost half-way through. We think it is poor practice to change legislation half-way through."
Whilst it has argued that ECO's funding should be switched to general taxation, E.ON opposes the other mooted changes, which include the cutting of targets to install expensive energy efficiency measures - in some examples costing as much as £10,000.
E.ON is closer to meeting the targets set by ECO than many other energy suppliers in the United Kingdom.
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