The Pollution Prevention and Control Bill - much amended by government in the lords after protests it gives too much power to the secretary of state - is facing similar criticism in the commons despite the redrafting.
Conservative spokesman Simon Burns told the commons he would 'get to the bottom' of the legality of the Bill and whether adequate parliamentary controls would be in place.
Earlier, speaking during the Bill's second reading, he said: 'What causes me most concern is not the philosophy that the Bill reflects or the regimes that it would introduce,for those command widespread cross-party support. I am most concerned about its constitutionality.
He said parliamentary rules would not allow the commons to amend any regulations proposed.
Environment minister Michael Meacher said a set of regulations was far more flexible than primary legislation to tackle issues expeditiously. A proper degree of parliamentary control was ensured because the regulations would be subject to the affirmative resolution - that is, approved by a vote of the house rather than the negative procedure by which they were debated only when objections were raised.
Mr Burns refused to accept the assurances and said any regulations should be measured against predetermined criteria with a point of reference in the primary legislation.