It was considered so important that two top cabinet members, finance minister Gordon Brown and foreign minister Jack Straw, were hauled back from foreign trips to vote on the assumption that there might be only one or two votes in it.
Little wonder that many senior members of Mr Blair's cabinet, including John Prescott, the deputy prime minister, Gordon Brown, the chancellor and Jack Straw, the home secretary, have let it be known that they would prefer to stick with the current first-past-the-post system.