Senior White House and Department of Health and Human Services officials were told last spring of problems that could derail the launch of, according to a report compiled for the Obama administration and obtained by the Washington Examiner.

Even though senior administration officials repeatedly gave assurances about the readiness of the Obamacare website, they were privately told by outside consultant McKinsey & Co. of risks threatening the functionality of the online marketplaces.

A 14-slide presentation warned of “insufficient time and scope of end-to-end testing,” that the website would launch at “full volume” rather than staggered over time, so-called “stacking” of all phases and “significant dependency on external parties/contractors.” The report also flagged “multiple definitions of success” and “evolving requirements” for the website.

According to the House Energy and Commerce Committee, which provided the report to the Examiner, White House and HHS senior officials were briefed on the findings between March 28 and April 8.

White House Chief Technology Officer Todd Park attended a meeting about the report on March 28. Among those present at an April 4 briefing were Health and Human Services Secretary Kathleen Sebelius and Centers for Medicare & Medicaid Services Administrator Marilyn Tavenner. Jeanne Lambrew, Obama's health policy adviser, and then-White House deputy chief of staff Mark Childress were briefed on the report April 8 at the White House, according to the House committee.

For weeks, President Obama has been on the defensive over the problem-ridden website and his broken promise that all Americans could keep their current insurance plans under Obamacare. The president's approval ratings have hit all-time lows in a series of recent polls.

White House officials, however, dismissed GOP attempts to pounce on the previously undisclosed report.

“As we have said many times now and as has been frequently reported, flags were definitely raised throughout the development of the website, as would be the case for any IT project this complex,” White House spokesman Eric Schultz said.

“Those issues, including the ones from 6-months before launch, were, in turn taken-up by the development team housed at CMS. But nobody anticipated the size and scope of the problems we experienced once the site launched,” he added.

White House officials said that the McKinsey analysis was not a technical review of the website’s functionality but a study meant to identify risks that could affect the consumer experience.

The report did not explore whether the Oct. 1 launch for open enrollment in Obamacare should be delayed.

CMS officials said fixes were made in response to the report and that the study was standard operating procedure.

“The review was completed six months before the beginning of open enrollment, was in line with industry best practices, and was followed by concrete action to address potential risks — as was intended,” CMS spokeswoman Patti Unruh said.

However, Republicans accused the White House of misleading the public about the foundation of the president’s signature domestic achievement.

“On April 18, Secretary Sebelius appeared before our committee, looked us in the eye, and repeatedly testified everything was 'on track and on time,’ ” Energy and Commerce Chairman Fred Upton, R-Mich., said. “We now know that was not the case and the secretary was aware implementation was in trouble.”

“The administration was on track — on track for a disaster, and yet officials refused to be transparent with the Congress and the American people,” Upton added.