In the ad, a neurosurgeon warns that a government-run health care system will lead to the rationing of procedures and medicine.

The refusal by to run the ad has raised questions from the League of American Voters, with one question targeting ABC's health care special hosted at the White House which aired last June. ABC says they do not allow "partisan" ads on their networks, and NBC said they questioned some of the ad's factual claims and would reconsider it with some revisions.

"It's a powerful ad," said Bob Adams, executive director of the League of American Voters, a national nonprofit group with 15,000 members who advocate individual liberty and government accountability. "It tells the truth and it really highlights one of the biggest vulnerabilities and problems with this proposed legislation, which is it rations health care and disproportionately will decimate the quality of health care for seniors."

Watch the ad: