By Will Grant
BBC News, Venezuela
Mr Chavez's appearances on Alo Presidente often last for a long time
Venezuelan President Hugo Chavez has cancelled an edition of his TV show, Alo Presidente.
The cancellation comes amid arguments with the Peruvian writer Mario Vargas Llosa about a live televised debate.
Mr Chavez has broadcast some 18 hours of special editions of Alo Presidente since Thursday to celebrate the 10th anniversary of the programme.
But the latest edition has been withdrawn at late notice with no explanation from the government.
After around 18 hours on air over the past two days, the third instalment of President Chavez's marathon programme was suspended with no official reason given.
"It will go ahead as planned on Sunday "from the state of Guarico," a government spokesperson said.
The latest show should have started at 1100 local time on Saturday but by mid-afternoon it had become clear that the broadcast was not going ahead.
The decision to suspend Alo Presidente comes after a series of challenges and counter-challenges about holding a televised debate with the Peruvian writer - and arch-critic of President Chavez - Mario Vargas Llosa.
Mr Vargas Llosa is currently in Venezuela to attend an opposition-led seminar about democracy and authoritarianism in Latin America.
The last time Mr Chavez was on air, he challenged to Mr Vargas Llosa and his colleagues to come onto the programme and debate live with another group of assembled Latin American academics who are sympathetic to Mr Chavez.
President Chavez said he would moderate the discussion. Amid insults on both sides, Mr Vargas Llosa retorted he was only interested in debating directly with President Chavez and that the president's offer was not a serious one.
The Venezuelan leader has described his four-day TV extravaganza as a "soap opera", promising that there would be singing, debate and "a little bit of everything".
In the end, an episode of this unique political soap opera may have been suspended, but avid watchers are still likely to tune in for the final instalment on Sunday night.