Kathleen Miller

The U.S. Senate voted Thursday to repeal the core of the Affordable Care Act, bringing Congress closer to sending legislation to President Barack Obama for the first time that would dismantle his signature domestic achievement.

The U.S. Department of Health and Human Services told contractors not to cooperate with Congress’s efforts to investigate work related to the Obamacare website, a top Republican lawmaker said.

President Barack Obama’s health agency said it has spent $319 million building an online health-insurance marketplace through October.

After three years of trying to dismantle Obamacare, House Republicans now are seeking to use the website’s flawed debut to hasten its collapse.

The introduction was so rushed that, as recently as last week, the exchange’s computer code contained placeholder language that programmers typically use in preliminary drafts.