As lawmakers wage battles over the future of President Barack Obama's health care law on Capitol Hill, more than 11.5 million people have signed up for health insurance through state and federal exchanges the Affordable Care Act created, according to a government report.

The numbers, which run through Dec. 24, are 286,000 higher than last year's tally. The exchanges allow most people who do not have employer-sponsored insurance to buy tax-subsidized coverage.

Officials at the Department of Health and Human Services who are concerned about Obamacare's possible repeal are pointing to the latest figures to counter attacks that the law has failed. They caution that waiting for details about a replacement plan from Republicans likely would create chaos in the marketplace, causing more insurance companies to leave the exchanges and raising prices.

"Repeal and delay leaves our entire health care system hanging over a cliff, and we’d likely go over it," Aviva Aron-Dine, senior counselor to the secretary at the Department of Health and Human Services, said in a call with reporters Tuesday.

Ben Wakana, spokesman for the Department of Health and Human Services, said the maneuver "means gambling on people's health care while they wait to come up with a replacement plan," and noted that Republicans haven't coalesced around health care reform policies since the passage of Obamacare nearly seven years ago.

On Tuesday, House Speaker Paul Ryan, R-Wis., said Obamacare would see a "concurrent" repeal and replacement plan, though he did not release details of what particular proposals would be introduced.

The Department of Health and Human Services wrote in a release accompanying the latest enrollment figures that "a broad cross-section of Americans continue to rely on the Marketplace to access affordable, quality coverage." The data presented broke down enrollment for the federal exchange, Healthcare.gov, by gender, race, age and for people who live in rural areas.

The report, however, did not contain information about whether consumers who signed up for plans had medical concerns requiring ongoing treatment and coverage, and it did not survey people's motivations for signing up for coverage – including whether they were doing it to comply with the mandate that requires people to obtain insurance or pay a penalty of $695 or more.

Insurance companies that have left the exchanges have complained that the risk pool of customers in these plans is overly burdened by people who have costly medical care. As insurers cited losses and exited the exchanges last summer, prices for premiums surged, and opponents of the law said Obamacare was headed for a "death spiral."

To counter the accusations, officials in Tuesday's call cited a report by the White House's Council of Economic Advisers released on the same day that concluded premium hikes were a one-time adjustment and rebutted claims that the system was in a "death spiral."