Maseru - The former prime minister of Lesotho returned to the landlocked mountain kingdom on Sunday, pledging to win back power two years after fleeing in fear of his life.Thomas Thabane, leader of the All Basotho Convention (ABC) party, was greeted by thousands of supporters at a rally in the capital Maseru, as political instability threatens to again shake the country."Prime Minister (Pakalitha) Mosisili must open parliament... so that we can legally overthrow his government and take over," Thabane said."It is clear that he no longer has enough parliamentary seats to govern this country."Lesotho has been hit by power struggles since a failed coup in June 2014, which led to elections in early 2015 when Thabane narrowly lost power.Mosisili, of the Democratic Congress (DC) party, currently heads a fragmented coalition government that took power after the elections.Thabane, who said he fled after being tipped off about a plot to kill him, told the South African News24 website: "I am taking a huge risk by going back to Lesotho. The threat on my life is still there."In 2014, army chief Tlali Kamoli was accused of launching a coup against Thabane when soldiers attacked police headquarters, looted weapons and killed one officer.A senior general, who was seen as close to Thabane, was gunned down in June 2015 by soldiers.South Africa and the Southern African Development Community (SADC) bloc have repeatedly called for peace and political reform in Lesotho.Thabane, who was based in South Africa during his self-imposed exile, used his speech on Sunday to criticise the SADC for lack of support. Surrounded by South Africa, Lesotho is one of the world's poorest countries and its economy is heavily dependent on its larger neighbour, to where it exports water and hydroelectric power.Two other opposition leaders also returned with Thabane on Sunday.The three opposition parties are pushing for a no-confidence motion against Mosisili's government when parliament reopens on February 24.Lesotho, a constitutional monarchy, was a British protectorate known as Basutoland before independence in 1966.