WASHINGTON -- At least one Democratic political strategist has gotten a warning from the White House to never appear on Fox News Channel, an outlet that presidential aides have depicted as not so much a news-gathering operation as a political opponent bent on damaging the Obama administration.

The Democratic strategist said that shortly after an appearance on Fox he got a phone call from a White House official telling him not to be a guest on the show again.

The message was, "We better not see you on again," said the strategist, who spoke on condition of anonymity so as not to run afoul of the White House. An implicit suggestion, he said, was that "clients might stop using you if you continue."

White House Communications Director Anita Dunn said that she had checked with colleagues who "deal with TV issues," and they had not told people to avoid Fox. On the contrary, they had urged people to appear on the network, Dunn wrote in an e-mail.

Patrick Caddell, a Fox News contributor and a former pollster for Democratic President Jimmy Carter, said he had spoken to Democratic consultants who said they were told by the White House to avoid appearances on Fox. He declined to give their names.

Caddell said he had not gotten that message himself. He added: "I have heard that they've done that to others in not-too-subtle ways. I find it appalling. When the White House gets in the business of suppressing dissent and comment, particularly from its own party, it hurts itself."

White House officials appear on Fox News, but sporadically and with "eyes wide open," as one aide put it.

David Axelrod, senior adviser to the president, appeared on Fox News Channel last week to talk about the results of Tuesday's off-year elections. Secretary of State Hillary Clinton also appeared on the network last week.

The White House has taken an aggressive stance toward Fox. Although President Barack Obama appeared on five separate talk shows one Sunday in September, he avoided Fox.

Last month, Dunn told CNN that Fox was, in effect, an "arm" of the Republican Party.

As the dust-up played out, Fox's senior vice president of news, Michael Clemente, countered: "Surprisingly, the White House continues to declare war on a news organization instead of focusing on the critical issues that Americans are concerned about, like jobs, health care and two wars."

Fox's commentators have been sharply critical of the Obama administration. After the president won the Nobel Peace Prize, Sean Hannity, who has a prime-time show on Fox, said Obama got the award for "trashing America."

Fox's audience is by far the largest of the cable networks, with an average of more than 2.1 million viewers in prime time this year, according to Nielsen Co. CNN is second, with 932,000.