PARIS (Reuters) - Michele Alliot-Marie resigned as French foreign minister Sunday following a series of gaffes over Tunisia which embarrassed President Nicolas Sarkozy and dragged his poor poll ratings even lower. A government source said she would be replaced by Defence Minister Alain Juppe, a heavyweight conservative who served as foreign minister and prime minister in the 1990s. Alliot-Marie presented her resignation in a letter she hand-delivered to Sarkozy, a copy of which was seen by Reuters. "I ask you to accept my resignation," the letter said. France is under pressure to take the right approach to the pro-democracy movement sweeping through North Africa, including former French colonies where the political elite has had close ties with authoritarian rulers. Sarkozy is expected to signal a new focus on foreign policy when he makes a hastily scheduled televised address later on Sunday. News Saturday that he would make a speech fanned speculation he would announce another reshuffle of a cabinet he has tweaked several times since taking office in 2007. The sources said the ruling UMP party's leader in the Senate, Gerard Longuet, was likely to succeed Juppe as defence minister. Sarkozy's Chief of Staff Claude Gueant, his right-hand man, would be appointed interior minister, replacing Brice Hortefeux, who would become a presidential adviser. Calls for Alliot-Marie to quit had grown louder in recent days following a series of blunders in her handling of the crisis in Tunisia, including taking a holiday there as protests raged. She accepted private plane rides from an associate of the now-ousted president Zine al-Abidine Ben Ali.