PSEG is pushing the bill, threatening to close its plants if the state does not provide lucrative financial incentives as New York and Illinois have done to avert the shutdown of nuclear units in those states. The nuclear industry is facing steep economic challenges in competing against cheap natural-gas plants.

But the subsidies are opposed by a broad coalition of business groups, energy competitors, consumer advocates, and environmental organizations. They argue PSEG has failed to prove the plants are not profitable and question why utility customers should bail them out.

It is not clear how much PSEG is seeking to prop up the plants, but opponents say the cost could run as much as $300 million or more a year for as long as a decade. If the ratepayer subsidies are too high, clean-energy advocates fear it will crowd out investments in renewable-energy alternatives, such as solar and wind power.

The lack of information left the Statehouse awash in rumors yesterday over a process that was remarkably opaque even for a lame-duck session. Typically well-informed lawmakers acknowledged not knowing details in the bill.