U.S. Sen. Chuck Grassley is continuing his fight against an Obama administration Web site urging supporters to push for health-care reform.

Grassley said Friday a memo from the Congressional Research Service backs his claim the site may violate federal rules on the use of public money.

Last month, Grassley complained that a form letter posted to a Health and Human Services Web site improperly asked people to "state your support" for health-care reform.

Grassley called it "propaganda," but the Obama administration defended the site.

A Congressional Research Service memo said this week the text of the letter urging that people "work with our congressional leaders" to pass health-care reform "might arguably be seen" as a potential violation.

Beth Levine, a Grassley spokesperson, said the senator is awaiting the administration's response before considering future steps.

Health and Human Services Secretary Kathleen Sebelius sent a letter to Grassley this week answering a series of questions about the Web site and reiterated its defense of it as "entirely legal and proper."