John McCain asked his donors and backers on Monday to "cease and desist immediately" from supporting advertising efforts that are not officially connected to his Republican presidential campaign but that promote his stance on political issues.

McCain, who has been a longtime critic of such independent expenditures, specifically singled out Republican media strategist and former McCain adviser Rick Reed and urged him to stop running ads that portray McCain and two of his congressional allies as leaders on national security and frugal government spending.

"Anyone who believes they could assist my campaign by exploiting a loophole in campaign finance laws is doing me and our country a disservice," McCain said. "I ask all of my donors and supporters, including Mr. Reed, to cease and desist immediately from supporting any independent expenditures that might be construed as benefiting my campaign indirectly. If you respect me or my principles, I urge you to refrain from using my name and image in any ads or other activities."

McCain's demand elaborated on a statement he issued Friday after The Associated Press first reported on the existence of a new group, the Foundation for a Secure and Prosperous America, that began running ads in South Carolina that were created by Reed. The group, established under tax laws as a 501(c)4 organization, is a nonprofit foundation that can raise money in unlimited amounts from donors whose identities do not have to be disclosed.

Republican rival Mitt Romney criticized McCain on Monday saying the foundation represented "an entire end-run on any effort to control campaign spending and offer transparency."

"It is the height of irony that the author of McCain-Feingold now has his supporters raising, apparently, vast sums of money, well above the contribution limits that normal citizens see, to support his campaign," Romney said, referring to McCain's co-author, Sen. Russ Feingold, D-Wis.

Independent groups can operate differently from political campaigns or political action committees, which are governed by the Federal Election Commission and can only receive limited individual contributions and whose donors must be disclosed publicly.

McCain was one of the authors of the 2002 law that eliminated unlimited contributions, or soft money, to political parties. In the aftermath of the law, political strategists shifted their attention to outside groups that could still obtain soft money and run ads on behalf of candidates provided they avoided expressly advocating their victory or their defeat.

McCain's support for changes in campaign finance law have not been popular with conservatives activists, who believe his proposals limit their free speech rights. Romney seized on that sentiment Monday.

The law, Romney said, "accomplishes in no significant way the purpose it was created to deal with, which is the influence of money in politics."

On Friday, Reed said the foundation planned to expand its television campaign. He also acknowledged McCain's role as an advocate of changing the influence of money in politics.

"It is our view, however, that the issue of campaign finance reform pales in comparison to the need to identify leaders who not only understand the threat of Islamic radicalism, but have the experience, judgment and resolve to support policies that will defeat it," Reed said Friday.