Leterme was the Prime Minister of Belgium from March 2008 to December 2008. He has formerly been Minister of Foreign Affairs, Deputy Prime Minister and Minister of Budget, Institutional Reforms, Transport and the North Sea in the Belgian federal government. He is also a former Minister-President of Flanders and Flemish Minister of Agriculture and Fisheries. Despite his French name, Leterme is Flemish. He is fluent in Dutch, French and English.
On 14 July 2008, facing the imminent failure to meet a self imposed deadline to enact "constitutional reform" consisting of further devolution of powers to the nation's three linguistic communities, Leterme tendered his resignation to King Albert II, the head of state. On 17 July, King Albert, after holding a flurry of consultations with leaders of political parties, labor unions, and the employers' association, rejected Leterme's resignation. Instead, the king appointed a three person commission of representatives of the linguistic communities to investigate how to restart the reform process. The commission was to report to the king by 31 July 2008.
On 19 December 2008 he offered his resignation to King Albert II after a crisis surrounding the sale of Fortis to BNP Paribas. On 22 December 2008 King Albert II accepted his resignation, along with that of his entire government. He remained Prime Minister until 30 December, when Herman Van Rompuy was appointed as his successor. On 24 November 2009, it was announced that Leterme would once again become Prime Minister, succeeding Van Rompuy, who had been selected to become the first President of the European Council.
On 22 April 2010 he once again offered his resignation to King Albert II after a key Flemish party Open VLD withdrew its support for the coalition government. An election followed in June, and since then Belgium's political parties have been attempting to negotiate a governing coalition. Leterme has remained as caretaker Prime Minister, but on September 13, 2011 announced that he would leave the post by the end of the year to take up the position of deputy secretary-general at the OECD.