Opposition politicians Gennady Gudkov and Vladimir Ryzhkov said Wednesday that they would seek criminal charges against those responsible for secretly filming them discussing plans for the upcoming protest rally and posting it on the Internet in an apparent bid to discredit them.

The video of Gudkov, a State Duma deputy with A Just Russia, and Ryzhkov, of the Party of People's Freedom, was filmed at the Akademia cafe near the Duma and was uploaded onto YouTube on Monday. The footage only came to the attention of bloggers on Wednesday.

Titled "Split of the Opposition, or Where Rzhavy Gudok Calls" — a play on the politicians' last names that can be translated as "a rusty horn" — the video shows them sitting face to face at a table and discussing the opposition demonstration planned for Feb. 4.

Shot with a hidden camera from a neighboring table, the poor-quality audio makes it difficult to understand exactly what is being said, but at one point the two men utter obscenities while discussing A Just Russia leader Sergei Mironov and opposition activist Alexei Navalny.

Interspersed throughout the 10-minute-long clip are brief snippets of text saying Ryzhkov and Gudkov "plan to head the party after the presidential election" in March, when they might "topple Mironov."

During the conversation, the two men mention the "creation of a European-style Social Democratic party," but the context is difficult to discern because of the poor sound.

Both Ryzhkov and Gudkov — a former KGB officer and deputy chairman of the security committee in the Duma — announced Wednesday that they planned to petition for a criminal case to be opened, especially because Gudkov is a state official.

"We had agreed on the meeting only half an hour earlier," Gudkov said, according to Interfax. "It proves that our phone conversations are tapped and we might even be being followed."

He insisted that the audio had been doctored and that he and Ryzhkov had no plans to overthrow Mironov.

In December, tabloid web site LifeNews.ru posted recordings of a phone conversation with Ryzhkov ally Boris Nemtsov making disparaging remarks about other opposition leaders. Nemtsov later apologized.

Pressed by Duma deputies including Gudkov, investigators opened an investigation into that incident, but no one has been charged.

Opposition figures say they consider the release of the recordings as aimed at provoking disagreements among the leadership.

About 20,000 people have signed up on Facebook saying they intend to go to the Feb. 4 protest.