France says it has launched a humanitarian mission with the assistance of Spain and Switzerland to help an ailing French-Colombian politician who has been held by Colombian rebels for the past six years. Lisa Bryant in Paris has more on the mission.

The French government says the mission will include a doctor and aims to help 46-year-old leftist politician Ingrid Betancourt, who has been held hostage by Colombia's Revolutionary Armed Forces or FARC since 2002. The plight of Betancourt, who holds both French and Colombian citizenship, is a popular cause in France where posters of her face are plastered on many public buildings.

In a recorded statement from the Elysee palace in Paris, French President Nicolas Sarkozy urged FARC commanders to release Betancourt, who is believed to be seriously ill.

Mr. Sarkozy said that by freeing Betancourt and other ailing hostages, the Colombian rebel group will offer relief to Betancourt's family and appease the international community. He said her release would open up the possibility of peace in Colombia and he urged FARC rebels to seize the opportunity.

The French government has divulged almost no information about the mission. French Foreign Minister Bernard Kouchner said it would leave as soon as possible. News agencies reported that a Colombian official told a local radio station it was already underway.

At a news conference in Paris, Betancourt's son Lorenzo said his mother is suffering from hepatitis B and a skin disease. Without a blood transfusion, he told reporters, she could die.

Lorenzo Betancourt suggested his mother is strong, despite her illness. She would go on to the very end, he said. But he said it was time for the FARC and the international community to act.

FARC is a Marxist guerrilla movement that has been fighting the Colombian government for more than 40 years. It is believed to be holding more than 700 people hostage in Colombia's jungles - including Betancourt.