The chairman of the House Oversight and Government Reform Committee issued a subpoena Monday for documents related to a Medicare Advantage demonstration project, after notifying the Health and Human Services secretary last week that he planned to push ahead.

Republicans have attacked the three-year demonstration, which would increase payments to private health care plans in Medicare, as a way to cover up cuts to the Medicare Advantage program that were included in the 2010 health care law (PL 111-148, PL 111-152). At a July hearing, panel Chairman Darrell Issa, R-Calif., called the project an “$8.3 billion election year bailout” and accused President Obama of using the funds “to buy an election.”

But on Monday, Elijah E. Cummings, the top Democrat on the Oversight panel, accused Issa of playing politics.

“Since HHS committed to producing the documents and is already in the process of producing them, this subpoena seems to be just for show ahead of the presidential election,” the Maryland Democrat said in an emailed statement.

Although the department delivered about 1,300 pages of documents to his panel last week, Issa said in an Oct. 19 letter that the information did not meet the committee’s request. He and Oklahoma Republican James Lankford, who chairs the Subcommittee on Technology, Information Policy, Intergovernmental Relations and Procurement Reform, sent a letter to HHS Secretary Kathleen Sebelius on Oct. 17 threatening to move forward with the subpoena process if the committee did not receive all of its requested information by 5 p.m. the next day. A committee spokesman said Monday that the subpoena had gone out.

Issa initially sent Sebelius a letter asking for documents related to the pilot in May. On Aug. 1, Issa and Lankford sent a request for new information and — maintaining that the department’s response had not been fully compliant — additional documents linked to the May letter. In a follow up Sept. 27, the lawmakers said they would consider forcing the department to turn over the documents if HHS “continues to ignore the committee’s request.”

The demonstration has been criticized by the Government Accountability Office (GAO), which issued a letter in March recommending that the department cancel it. The GAO cited the project’s $8.35 billion cost, among other things, and said its design makes it unlikely it will generate meaningful results.

But Sebelius told lawmakers in April that her department had no plans to cancel the project, which runs from 2012 to 2014. At the July hearing, an official from the Centers for Medicare and Medicaid Services said his agency was confident the demonstration would yield “very valuable information to determine how we can both accomplish the dual goal of reducing overall Medicare costs while substantially improving the overall quality and performance.”

The health care law created a bonus payment program that would reward Medicare Advantage plans that receive ratings of four, four and a half or five stars, with five indicating the highest-quality plans. The demonstration project extends the higher payments to plans that get three and three and a half stars and provides larger rewards for plans with four or more stars in the first two years.

GAO testified in July that the pilot offsets 70 percent of the health care law’s reduced payments to Medicare Advantage this year, although over the course of the three-year project about a third of the cuts would be offset.