By Maayan Lubell

(Reuters) - Prime Minister Benjamin Netanyahu delivered an unprecedented vilification of the Israeli media on Monday, accusing a leading television journalist of being part of a plot to bring down his right-wing government.

After declining to be interviewed by Channel Two anchorwoman Ilana Dayan for a piece investigating the workings of his administration and the role his wife plays in appointing officials, Netanyahu's office sent a written statement.

Dayan read it in its entirety on air, taking six minutes to deliver the tirade against her as she stood in front of the prime minister's office.

"It is time to peel the mask off the face of Ilana Dayan, who has shown once more that she has no professional integrity," the statement said.

"Ilana Dayan is one of the leaders of an orchestrated attack on Prime Minister Benjamin Netanyahu, intended to topple the right-wing government and bring about the establishment of a left-wing government."

The statement referred to popular disaffection with the media -- a survey last year found two-thirds of Israelis believe the media is left-leaning -- and reiterated the need for an overhaul of national broadcasting.

It said the public had lost trust in the main media organizations, which it said had abandoned all restraint in their propaganda against Netanyahu and his Likud government.

"Dayan's show...demonstrates perfectly why the media industry needs reform. The prime minister is determined to open the market up to competition that will add a greater variety of opinions, as well as an efficient national broadcaster."

The onslaught astonished commentators. While Netanyahu is known for his fractious relationship with the media, few expected such an angry and personalized assault.

It comes at a time when he and his close associates in the Likud party face criticism for their haphazard efforts to shut down the existing state broadcaster and set up a successor.

There has also been widespread coverage of allegations by housekeepers and other employees against Netanyahu's wife, who is often portrayed as a demanding figure.

That has compounded a feud between Netanyahu and leading newspaper group Yedioth Ahronoth, which campaigned against him ahead of his reelection last year.

Netanyahu has made no secret of his dislike for Yedioth and its publisher, Noni Mozes, and has largely avoided on the record interviews with the Israeli press, preferring to distribute statements and videos by YouTube, Facebook and Twitter.

Critics now fear he is going after broadcast outlets.

"What we see is an across the board attempt by Mr Netanyahu and his government to control all forms of media," said Elad Man, legal adviser of media watchdog the Seventh Eye.

"I don't think we should even try to imagine what will happen to Israel as a society and a democracy if those attempts succeed."

MEDIA MESS

In 2014, Netanyahu agreed to create a new public broadcast network, which says it will be ready to go on air in January. It has already hired 500 staff with plans to take on 150 more.

But now Netanyahu wants to pull the plug on the operation. He has not said why, but allies have talked about the soaring costs while the chairman of his coalition, David Bitan, said in October it was because of its bias against Netanyahu.

"The corporation has been hijacked by people whose agenda is leftist and anti-government," Bitan told Channel Two, one of Israel's leading commercial channels.

He later said he had checked the Facebook pages of some journalists working at the new broadcaster and found them critical of the government.

Netanyahu's office did not respond to requests for comment for this story.

His volte-face over the network is now causing problems in his coalition. His finance minister says shutting down the broadcaster will cost far more than keeping it going and has threatened to withdraw his support.

He and Netanyahu agreed to set up a committee to tackle the issue, comprising officials from the finance ministry, the communications ministry and the prime minister's office.

Netanyahu showed up to the first meeting. One source said he told them he "could not put up" with the new broadcaster, and another quoted him as saying: "I am willing to call an election over this."

Netanyahu's culture minister, close ally Miri Regev, was quoted in newspapers as telling a cabinet meeting: "What is the Israeli Public Broadcasting Corporation worth if we are not in control of it?"

The row has raised concerns about declining media freedom in Israel.

The country's most widely read newspaper is a free sheet called Israel Today, owned by U.S. casino billionaire Sheldon Adelson, that is relentlessly pro-Netanyahu. The prime minister also serves as communications minister, giving him regulatory powers over the sector.

Freedom House, an international media freedom group, this year downgraded Israel's ranking to "partly free". Some commentators have compared Israel unfavorably to Turkey and warned of a wider clampdown.

That seems unlikely given how outspoken much of the press remains. But President Reuven Rivlin saw fit to comment last week, telling parliament in remarks seen as critical of Netanyahu: "Anyone in favor of public broadcasting cannot turn it into a mouthpiece for commissars."

To Yossi Verter, a political analyst for the left-leaning Haaretz newspaper, the moves by Netanyahu and his point-man Bitan have dangerous echoes.

"Netanyahu's emissary is on a death mission to destroy what's left of Israeli media," he wrote last week, describing Bitan's conduct as akin to the 1950s hearings by U.S. Senator Joe McCarthy against Communists and "subversives".

(Additional reporting by Lianne Back and Rami Amichay; editing by Luke Baker and Angus MacSwan)