AARP is pushing back against a bipartisan effort to move Social Security changes through Congress more quickly, setting up a fresh clash over one of Washington’s most sensitive policy debates. The group, which represents 38 million older Americans, has formally objected to the proposal.

The plan was designed to break a long-running Social Security stalemate on Capitol Hill. But AARP’s response suggests any attempt to speed up a broad overhaul will face major resistance, especially if it includes changes that could affect benefits.

At the center of the dispute is how lawmakers should handle reforms to a program that millions of retirees and near-retirees depend on. AARP’s stance signals that it does not want Congress to rush through a compromise without broader scrutiny of how the changes would affect older Americans.

The fight highlights the political difficulty of updating Social Security, even when support comes from both parties. With AARP drawing a clear boundary, the path to any fast-moving deal on benefits appears much more complicated.