NEW YORK >> Saying the NFL Players Association is “holding HGH testing hostage” after more than two years of squabbling with the league, the top Democrat on the House Oversight and Government Reform Committee warned today that Congress could get involved.

In a statement emailed by his office to The Associated Press, Rep. Elijah Cummings of Maryland said the union “continues to disregard its promise to implement HGH testing.”

He added: “Continuing to block HGH testing in this way essentially will force Congress to intervene, which nobody wants.”

The oversight committee held a hearing in December to take a look at the science behind blood tests for human growth hormone. HGH is a banned performance-enhancing drug that is hard to detect and has been linked to health problems such as diabetes, cardiac dysfunction and arthritis.

Two full NFL seasons have passed — and another is about to begin — without a final agreement on HGH since the August 2011 labor deal paved the way for testing.

In his statement, Cummings pointed to “extraordinary concessions from the NFL, numerous meetings with Members of Congress, and a parade of experts verifying the validity of HGH testing” and said: “After two years of negotiations, the NFLPA is now holding HGH testing hostage because of matters wholly unrelated to testing.”

The league says the main sticking point right now is whether Commissioner Roger Goodell — or someone he designates — will continue to hear appeals for violations other than a positive test. The NFL wants to keep that part of the drug policy in place, while the union would prefer a panel of arbitrators to hear appeals that involve breaking a law or the demonstrated use of a performance-enhancer without a positive test.

Hours before Cummings weighed in, the man who oversees the NFL’s drug program said the  union has “buyer’s remorse” about HGH testing. A union official retorted that “the only thing” the league cares about “is power.”

The latest public back-and-forth — featuring Adolpho Birch, the NFL senior vice president of labor policy and government affairs, and George Atallah, the NFLPA assistant executive director of external affairs — comes exactly two weeks before the first game of the 2013 regular season.

“There is a chance it won’t happen this season,” the NFL’s Birch told the AP. “I will also say there is a chance it will. I strongly hope that it does. I would have said the same thing last year. I would have said the same thing in October 2011.”

Noting that the union wants to change the appeals process for certain types of cases, Birch said: “If their interest is in advancing the interests of players who play clean, and reassuring the public we have competitive integrity, and restoring public confidence … we can get this done. If their interest is worrying about people who have broken the law, and how to protect them, then we’ve got more of a problem.”

Birch mentioned concessions he said the NFL has made during negotiations, including dropping its desire to increase suspensions for a second offense from eight games to 10 games.

The union’s Atallah said players have been asked to vote twice on whether to allow Goodell “to keep his appeal authority for violations of law, and two times the players have said, ‘No.”’

“I don’t expect the players’ position to change on that,” Atallah said in a telephone interview. “None of this stuff can move forward, none of the policy can change, without a vote. That’s how our constitution works. (NFLPA executive director DeMaurice Smith) can’t unilaterally agree to anything without taking it to a vote.”

Earlier today, the NFL issued a statement from Birch in which he said “it is time for the NFLPA to stop the delay tactics.” He called the desire to change the appeals process “simply a case of buyer’s remorse, and an effort to renegotiate part of a long-term agreement that they have now decided they don’t like.”

Atallah responded via his Twitter account, linking to a page on the NFLPA website that contained his reply: “The only case of buyer’s remorse is the attached letter that the NFL agreed to weeks ago. Our signature is on it. Sign it, like you agreed to, and we start drawing blood from players immediately. Your refusal to sign it confirms that the only thing you care about is power.”

Posted below his statement was what Atallah said was the signature page — with Smith’s handwriting, but not Goodell’s — from the sides’ agreement on how to carry out a population study. That would entail drawing blood from every player at training camp in 2013 to determine what level of HGH would constitute a failed test.

Team rosters must be reduced to the regular-season count of 53 by Aug. 31.

“The sooner they sign the population study letter, the sooner we can move forward,” Atallah told the AP. “But time is running out.”