Sondhi Limthongkul told a news conference on Tuesday at his office in Bangkok: "He is threatening newspapers to keep their mouth shut with costly civil lawsuits.
The Thai prime minister is suing Sondhi for $12 million.
"But that is fine with me because I was once bankrupt and am now solvent again. It wouldn't hurt to have such experience again," said Sondhi, whose media empire suffered during the 1997/98 Asian economic crisis.
But Thaksin's chief lawyer in two slander suits filed against Sondhi last week denied the accusation, saying journalists were free to do their job under the constitution as long as they did not distort facts.
Civil and criminal suits
Thaksin filed separate civil and criminal cases accusing Sondhi, his co-host and his production house of slandering officials in a television show since taken off the air.
The suits said Sondhi and co-host Sarocha Pornudomsak had accused Thaksin of being disloyal to the monarchy during a current affairs show aired on state-run Channel 9 on 9 September, Thaksin's chief lawyer Thana Benjathikul said.
The huge claim for damages was justified by Thaksin's "very high social status as the prime minister" and was not designed to deter the media from negative coverage of the government, Thana said.
"We can't gag the press since their job is to report," Thana said. "But if the media distort facts in their reports, the prime minister is entitled to use his rights as a citizen to sue."
"We can't gag the press since their job is to report. But if the media distort facts in their reports, the prime minister is entitled to use his rights as a citizen to sue"
Thai prime minister's chief lawyer
These are the first libel suits Thaksin has brought since he took power in 2001, although Shin Corp, Thailand's largest telecommunications firm which he founded, sued a media activist and the Thai Post newspaper for $10 million last year.
One of Thaksin's sisters filed criminal and civil libel cases against an opposition politician and the Thai Post in July demanding 500 million baht ($12 million) after the newspaper reported the politician's allegations of graft.
Those cases are still being tried.
Media watchdogs and government critics accuse Thaksin of bullying newspapers, most of them privately owned, by using government advertisements as bargaining chips for positive coverage.
Producers at television and radio stations, most of which are owned by the government or the military, allege similar tactics.
The issue reached a crescendo last month when a leisure and entertainment tycoon believed to be a close Thaksin ally tried to take over a prominent newspaper.
The bid by Paiboon Damrongchaitham produced a passionate outpouring of accusations that Thaksin was using his friend to influence Matichon, a leading political daily with a circulation of 400,000. The tycoon backed down.
Sondhi, once a staunch Thaksin supporter, took his show on the road after it was pulled from television.
He staged it twice at a Bangkok university, drawing thousands of people with hard-hitting attacks on Thaksin and his government.