If that deadline holds — several others have been extended as the law has rolled out — McDonnell said he intends to opt for the federal exchange, at least for now. That represents a shift for the governor, who previously said that if the law stood, he would prefer to have Virginia control its own exchange.

McDonnell said there are too many unanswered questions — how much a state-run exchange would cost, how well the federal version will work, whether the private sector might fill the niche — to move ahead on a Virginia exchange. He said his letters to President Obama and Health and Human Services Secretary Kathleen Sebelius, seeking clarification in a number of areas, have gone unanswered.

“I don’t want to buy a pig in a poke for the taxpayers of Virginia,” McDonnell said. “Without further information, the only logical decision for us is to use the federal option.”

McDonnell noted that Virginia would have up to two years to shift course and move into a state-based exchange if it later decides that would be better.

The governor also said he would not expand Medicaid — something the law had tried to force on states but the Supreme Court made optional — unless the health-care program for the poor and disabled is greatly reformed. The federal government has promised to pick up most of the tab for the expansion, but McDonnell said he doubted that Washington had the means to make good on that.