London - Four and a half months after the voters threw it out of government, Britain's Labour Party has a new leader, 40-year-old Ed Miliband.

The Labour Party is famous for its fratricidal conduct after it loses an election but in this case the word is more than usually apt. Coming a close second to Ed Miliband was his older brother, David.

Not since Cain threw down with Abel has there been a fraternal rivalry to match it, if the British press is to be believed.

Up until the last few days, 45-year old David was considered the front runner. Indeed had been regarded as the man most likely to be the next leader of the party since about 18 months into Gordon Brown's tenure as prime minister. By then it was clear that Brown was not up to the job and would be leading Labour to defeat at the next election. Speculation on who would follow him coalesced around David Miliband. He is reputed to be beyond smart. He was running Tony Blair's in-house Downing Street policy think tank before he turned 30, and was, if the pictures are to be believed, Secretary of State Hillary Clinton's favorite lunch partner at summits. He was expected to walk over the competition to replace Brown. Until his little brother threw his hat in the ring.

Ed Miliband, five years younger, was perpetually in his brother's shadow until last December's Copenhagen Summit on Climate Change. As Britain's environment secretary, Ed Miliband fought gallantly to prevent the summit from collapsing into acrimony and inaction. He failed. But his non-stop work behind closed doors and shirt-sleeve appearances in front of TV cameras projected him into the top tier of possible successors to Gordon Brown.

On television, Ed is fluent and likable where big brother comes off as stiff and aloof. He is too young to have been an intimate of the hated Tony Blair — yes, Blair may get big receptions in America but he his viscerally hated by the Labour party that he led to an unprecedented three election victories. David Miliband's intimacy with Blair counts against him.

The brothers are physically different. David is tall and angular and moves like Ichabod Crane in a Savile Row suit. Ed is shorter, rounder, more relaxed — huggable and empathic.

The essential difference between them, in the short hand of British politics, is that Ed is slightly more to the left than David. David would say don't forget the political center when making policy. Ed would say, our grass roots' needs should be our priority. Both would say the austerity measures being contemplated by the Con-Dem coalition are foolish and will hit ordinary people too hard.

Chips off the old block

The Cain and Abel storyline is manufactured, but the Miliband of Brothers' true-life backstory is one of the most compelling in British political history.

To begin with they are Jewish and their family only recently arrived in Britain. Their father got out of Nazi Europe after walking two days from Brussels to the North Sea coast and getting on the last boat from Belgium in May 1940. Their mother spent the war being sheltered by a Catholic family in Poland. She was one of the few in her family to survive. In all, 80 relatives of the brothers perished in the Holocaust.

Following the war, the pair's father, Ralph Miliband, took a degree in politics at the London School of Economics and became one of the most prominent left-wing intellectuals in Britain. He was a leader of the "New Left," a movement that was sparked by the Soviet invasion of Hungary in 1956 and was given impetus by the Vietnam War.

The elder Miliband made his academic reputation as an outspoken critic of the Labour Party from the left. Labour, in theory, was a socialist party, but Ralph Miliband saw its leaders as completely cut off from the working masses that founded it. His 1961 work "Parliamentary Socialism: A Study in the Politics of Labour" critiqued how the party had become a servant of the existing power structures in Britain rather than the people. This was followed in 1969 by "The State in Capitalist Society." The book pointed out that "the state" was an interconnected series of elites, made up of people drawn from the world of business, the military, the academy and the civil service. These elites' self-interest lay in perpetuating their power, not serving their constituents.

The critique — made when Labour was in government — was radical at the time. Today it is the conventional wisdom of Labour Party supporters as they assess the 13 years of the Blair-Brown government. During that time, power elites did better than ordinary folk, as demonstrated by bankers' pay and decisions made in the teeth of popular opposition, such as to go to war in Iraq.

It is this thinking that puts Ralph Miliband's oldest son, David, at a slight disadvantage in this contest. He is identified, rightly or wrongly, with those decisions.

The voting rules for party leader are based on preference voting. Rather than choosing just one candidate, Labour Party voters rank the five candidates by preference. David Miliband is expected to win the most first-choice votes but not a clear majority of them. Little brother Ed is likely to be everybody's second choice and so has a very good shot at actually winning the prize.

The grass roots

Late summer. Sunday afternoon. The streets of Westminster in Central London are empty except for a small cluster of people outside the evangelical meeting hall the Emmanuel Centre, who seem to be queuing up for a revival meeting.

David Miliband has convened a meeting for 1,000 community activists his organization has trained to lead the revival of the party at grass roots. The crowd demonstrates the essential difference between Labour's grass roots and activists for the Conservatives and Liberal Democrats.

It is an urban mix. About 40 percent are people of color, mainly African and Afro-Caribbean. The crowd is also young and features different economic backgrounds. When the other parties get together it is a very white, middle-aged, middle-class occasion.

The concerns of Labour activists are different as well.

Ben Pearce, a chemistry student with an interest in foreign policy, is a David Miliband supporter because, "there is no other candidate with comparable empathic views. As foreign secretary he was a very strong supporter of human rights."

Julian Haring, who lives on disability benefits, is not really a supporter of David Miliband. He thinks he isn't left-wing enough. Haring would prefer that a more thorough-going social democrat lead the party but he accepts the reality that that might not get Labour back into power. "David Miliband is eminently electable," he said.

The importance of electability can't be underestimated as a factor in the selection of a new Labour leader. Coalition government in Britain is something new and the honeymoon period between David Cameron's Conservatives and Nick Clegg's Liberal Democrats will officially come to an end next month when the coalition's spending review is published. It will outline just how deep the cuts to government spending will be in the next few years.

If they are as draconian as expected, the fault lines in the coalition will start to slip dramatically. The government might fall and a new general election would have to be called.

The baby-faced Ed Miliband will have to learn quickly to project his "electability" beyond Labour's membership. He may have to put himself forward as a plausible Prime Minister sooner rather than later.