(Reuters) - About 2.2 million people, or more than one in every four Americans who signed up for private health coverage under President Barack Obama's healthcare reform law, have inconsistent data in their applications that could lead to them losing coverage in isolated cases, officials said on Wednesday.

Republicans, who have made the law known as Obamacare a top issue for November's midterm congressional elections, pounced on the disclosure as fresh evidence that it poses an unworkable burden for Americans.

But officials denied that the data issues rise to the level of problem enrollments, saying consumers in many cases included data on income, citizenship and immigration that is more up to date than federal records show. They said most of the problems will be sorted out by the end of the summer.

The data discrepancies, first reported by the Associated Press, surfaced a day before the U.S. Senate is scheduled to take up a final confirmation vote on Obama's nomination of Sylvia Mathews Burwell as Secretary of Health and Human Services, the official chiefly responsible for Obamacare implementation.

More than 8 million people enrolled in private health insurance from October through mid-April via new online healthcare marketplaces established under the law in all 50 states.

The marketplaces provide subsidized coverage for consumers with qualifying income but the information must be checked to confirm that it is accurate. Data errors that go unaddressed can lead to demands for repayment and even coverage cancellations.

“A 25 percent error rate is simply unacceptable when it comes to proper use of scarce taxpayer dollars. Even worse, today’s announcement once again illustrates how the President’s bloated health care law has left American families and taxpayers in financial limbo," said Senator Orrin Hatch, the top Republican on the Senate Finance Committee.

The U.S. Centers for Medicare and Medicaid Services (CMS) released a report showing that 1.2 million people filed health insurance enrollment applications with questionable income data, while 461,000 had issues with citizenship and 505,000 with immigration.

CMS said 59 percent of the applications are within a 90-day window for resolving data problems and said that "thus far, the vast majority of cases are resolved affirmatively."

Consumers experience regular changes in income and various life circumstances and the law accounts for these kinds of situations," CMS sad. "It is not surprising that there are income discrepancies given that this is a brand new process."

But the agency also acknowledged that some applications could be terminated if unresolved.

"Two million consumers are not at risk of losing coverage -they simply need to work with us in good faith to provide additional information that supports their application for coverage and we are working through these cases expeditiously," CMS spokesman Aaron Albright said.

Barack obama