On February 19, 2007, the French parliament voted to amend the French Constitution to include an explicit ban on the death penalty. In a special joint session of both the National Assembly and the Senate at the Palace of Versailles, the amendment passed by a vote of 828-26. The joint session also voted 449-203 to approve a constitutional amendment guaranteeing the French president sovereign immunity while in office but introducing the possibility of impeachment. The measure had been previously approved by the National Assembly in January 2007 and called for US-style impeachment procedures to check the powers of France's presidency. Under the new provisions, the president can refuse to testify while in office, but, in cases of a "neglect of his duties manifestly incompatible with the exercise of his mandate," a two-thirds majority of either house of parliament can authorize impeachment proceedings.