An amendment to allow insurers to sell plans that don't comply with Obamacare was not added to a new version of a Senate healthcare bill, according to Sen. Mike Lee, R-Utah, who helped draft it.

Lee tweeted Thursday that something based on the amendment was included in the bill but "I have not seen it or agreed to it. I am withholding judgment and look forward to reading it."

The decision to exclude the amendment comes a day after major insurer groups blasted it for potentially raising premiums.

The amendment authored by Lee and Sen. Ted Cruz, R-Texas, would have allowed insurers to sell plans that don't comply with Obamacare insurer mandates such as protections for people with pre-existing conditions. The catch was they had to at least sell a plan that does.

But experts and insurers questioned whether people with pre-existing illnesses such as cancer or diabetes would face higher premiums. The thinking goes that only sick people would buy the Obamacare plans and healthy people would go to the ostensibly cheaper non-Obamacare plans.

It remains unclear what the new provision is. An outline of the new version provided to the Washington Examiner does include an option aimed at lowering premiums by allowing individuals to use subsidies toward the purchase of catastrophic plans that would have higher deductibles.