WASHINGTON – Maine’s Democratic candidate for U.S. Senate, Chellie Pingree, became a subject of controversy as Congress made its first major effort Wednesday to cut the prices that seniors pay for their prescription drugs.

Pingree originally had been requested to testify on how to provide a prescription drug benefit under Medicare before a House Ways and Means Committee hearing on Wednesday. However, the invitation was canceled abruptly by Republican leaders Tuesday after it was discovered that Pingree is the Democratic candidate running against Maine Republican Sen. Susan Collins.

Collins’ spokeswoman said Tuesday she knew nothing of the hearing or the decision by House Republicans to cancel Pingree’s appearance.

Pingree had been named as Rochelle Pingree on a publicized witness list and identified as a fellow with the Washington-based Center of Policy Alternatives.

During opening comments, Rep. Bill Thomas, R-Calif., the committee chairman, said he did not want to mix politics with policy during committee hearings.

“The chair will not allow candidates for political office to be factual witnesses, whether they be Democrats, Republicans, men, women, Libertarians, Green or others,” Thomas said.

Alluding to the partisan warfare that frequently erupts in the narrowly divided Congress, he added: “We ought to minimize the opportunity for continuing to bite at each other from a political perspective.”

Democrats, who have little say over the committee process as the minority in the House, protested that they selected Pingree because she is nationally acclaimed for her work to bring down prescription drug prices.

“Chellie Pingree has challenged the pharmaceutical industry head-on, which is exactly what we’ll have to do to get a meaningful prescription drug benefit for all seniors,” said Rep. Pete Stark, D-Calif., who selected Pingree to testify. “She has testified nationwide on Maine’s efforts to provide prescription drug coverage for seniors and is widely recognized as an expert on the subject.”

As senate majority leader in the Maine Legislature, Pingree sponsored successful legislation two years ago to establish the Maine Rx program, which would allow the state to negotiate wholesale prices for drugs with pharmaceutical firms. The program has been blocked by a legal challenge from the drug industry and awaits a ruling by the U.S. Supreme Court.

Republicans held their ground Wednesday as they defended their decision to exclude Pingree from the hearing. They also said that Democrats had a wide pool of experts to choose from for their one witness who could have offered more helpful testimony than Pingree.

“I would much prefer that the Democrats would have brought someone to the table that had national experience in policy-making,” said committee member Rep. Nancy Johnson, R-Conn. “To imagine that there wasn’t an expert that could have been called to the table on the other party’s side and made points of interest to them is simply ludicrous.”

At her campaign headquarters in Portland, Pingree disputed Johnson’s claim.

“States are often the laboratory for democracy,” Pingree said. “State-level solutions often go onto being national solutions.”

Pingree added that she has traveled around the country to address state legislatures and industry associations about pricing structures on prescription drugs.

Rep. Charles Rangel of New York, the ranking Democrat on the Ways and Means Committee, said politics and policy would never be divorced from each other when it comes to a subject like prescription drugs.

“I don’t see how this could not be political,” Rangel said. “We’re dealing with old folks who can’t afford to pay for the prescriptions they need.”