Republican U.S. Senator Ted Cruz on Sunday said he opposes the latest version of a Senate attempt to repeal Obamacare, casting doubt on the healthcare bill’s chances of passage, Politico reported.

Cruz, a Texas conservative, does not support the bill introduced by Senators Bill Cassidy and Lindsey Graham, and said Utah Republican Senator Mike Lee is also unlikely to support the measure, Politico reported.

It said Cruz told the Texas Tribune festival in Austin, Texas that amendments that he and Lee proposed to bring down the costs of Obamacare premiums had not been included in the most recent draft of the bill.

Cruz joins Republican Senators Rand Paul and John McCain, who have also said that they couldn’t support an Obamacare repeal, according to The Hill. Republican Senator Susan Collins (Maine) also said Sunday that it would be “difficult to imagine” her voting to repeal the Affordable Care Act.

This story is still developing.