Saif al-Islam Gaddafi has rejected calls for his father Muammar Gaddafi to step down as Libyan leader Reuters

Western powers attacking Libya have made themselves "legitimate targets" for retaliation, the son of Muammar Gaddafi has warned.

Saif al-Islam Gaddafi rejected calls for his father to quit Libya as the price of peace with the rebels fighting to overthrow him.

"To tell my father to leave the country, it's a joke, he told the French TV channel TF1. "We will never surrender. We will fight. It's our country.

"We have to fight for our country and you are going to be legitimate targets for us."

Asked if he had a message for the French president, Nicolas Sarkozy, one of the prime movers in the Nato offensive, Gaddafi replied: "You are not going to win. You have no chance, zero chance, to win the war here.

"If you are angry with us because we are not buying the Rafale airplanes, you should talk with us," he added, a reference to the Dassault-built French warplane that Paris had been trying to sell to Tripoli before the uprising against Gaddafi.

"If you are angry with us because oil deals are not going well, you should talk to us. Rebels will not give you anything because they are not going to win."

The Libyan leader's son, who like his father is facing an international arrest warrant on charges of crimes against humanity, claimed the regime was prepared to make concessions to some western demands.

"You want democracy, we are ready," Saif said. "You want elections, we are ready. You want, what, a new constitution? We are ready. Ceasefire? We are ready. But, the other side is refusing, all the time."

In an audio message played to tens of thousands of supporters in Tripoli's Green Square on Friday, Gaddafi urged Nato to halt its bombing campaign or risk seeing Libyan fighters descend on Europe "like a swarm of locusts or bees".

The conflict in Libya is in virtual stalemate, with rebels on three fronts unable to make a decisive advance towards Tripoli and growing strains inside Nato about the cost of the operation and the lack of a military breakthrough.

It was reported on Monday that rebel commanders had slowed their advance on Tripoli because they feared an all-out offensive would cause heavy civilian casualties. The rebels were less than 60 miles from Tripoli, British Forces News said, but claimed they were waiting for an uprising in the capital before they attacked.

Libya will be on the agenda at talks between Russia and Nato on Monday in the southern Russian resort of Sochi. Russia has criticised the bombing campaign, saying the mission has lost its original focus on protecting civilians and now aims to remove Muammar Gaddafi.