Just a point of clarification. The description of Mr Ed's election to the leadership does not fit in with someone who "...stabbed his own brother in the back, at the 11th hour, to get the top job? "
After nominations opened three potential candidates - including Milliband, E - complained that the deadline for entries was too tight (candidates need to secure the support of 12.5% of the Parliamentary Labour Party) and the deadline was duly extended.
The reason David Milliband was not elected leader was because of the composition of the electorate entitled to vote. These are split into three groups: The party's MPs and MEPs; Labour Party members; and what are euphemistically known as "affiliated members". These are not necessarily members of the Labour Party but are individual members of affiliated organisations, such as trade unions and socialist societies. These far outnumber the first two groups taken together (211k associate members took part in the election compared to 126k Party members and 266 MPs/MEPs). As if that were not bad enough, absolute numbers are not considered when counting the vote. Each of the three sections contributes one third towards the vote meaning that the votes of 266 MPs/MEPs are given the same weight as 126k party members or 211k associate members. Couple this with the "Alternative Vote" system and you could not contrive a more ridiculous system if you tried. Labour lauds this system as "one man one vote" but it is clear that one vote from an MP/MEP outweighs that of a party member by about 470 to one and that of an affiliated member by almost 800 to one.
However, even with that disadvantage (David was the preferred candidate of the MPs/MEPs and Labour party members in all rounds) Ed won. In fact he won every round of voting in absolute numbers and percentage terms because of the Union vote and if anybody did any back stabbing it was the Union barons.