Updated

The health care reform drive is in a holding pattern as Senate Democrats feud over an amendment that would allow cheaper re-importation of drugs from countries like Canada.

Sens. Byron Dorgan, D-N.D., and Olympia Snowe, R-Maine, together with 30 co-sponsors, introduced an amendment that would allow for an influx of cheaper prescription drugs from certain countries -- all under tight Food and Drug Administration restrictions. Dorgan has fought for the change for a decade, and it was previously supported by President Obama when he was a senator and White House Chief of Staff Rahm Emanuel when he was a representative.

But Sen. Tom Carper, D-Del., as well as at least one other Democrat, according to Dorgan, have put the brakes on any action on the amendment. It's up to Senate Majority Leader Harry Reid to settle the dispute in order to move forward on health care reform.

Carper defends his opposition by pointing to a letter he received earlier this week from the FDA laying out its concerns.

The letter, obtained by Fox News, outlined "four potential risks" -- that any such drug might not be safe, because it "was not subject to a rigorous regulatory review prior to approval; it "may not be a consistently made, high quality product because it was not manufactured in a facility that complies with appropriate good manufacturing practices;" it might have "differences in composition and manufacturing;" and the drug could be "contaminated" or "a counterfeit due to inadequate safeguards in the supply chain."

But Sen. John McCain. R-Ariz., another co-sponsor, says he knows the real reason for the resistance. "We all know what this is about. We all know it's the deal that Pharma cut … Come on, let's not kid each other. It's all about they made a deal with Pharma, and Pharma wants that deal to hold. That means no drug re-importation, no competition."

McCain was referring to the deal the White House struck earlier this year with the Pharmaceutical Research and Manufacturers of America (PhRMA). As part of it, the industry pledged an $80 billion reduction in costs and the administration agreed not to push for anything beyond that -- meaning re-importation.

Dorgan, incensed by the block, told reporters he is prepared to hold up any action on health care reform over the matter.

"I insist that we get our vote," he said.

Reid, who according to an aide has not taken a position on the amendment, would then have to file a procedural move that takes 60 votes to overcome if he wants to move forward on his health care bill.

Dorgan said he has many new protections in the new version of the re-importation legislation and that the FDA's letter "could have come from a copy machine," arguing that the concerns were just copied from previous years. Dorgan accused Carper of not reading the amendment.

The FDA makes clear that Dorgan has made improvements, however, and vows, in the letter, to work with the senator "to develop an avenue for the importation of safe and effective prescription drugs from other countries."