Every previous Labour government has provoked a major rebellion from the left after it betrayed the hopes that had led to its election.
The collapse of Ramsay MacDonald’s government in 1931 pushed the entire Labour Party to the left. It also strengthened the forces, inside and outside the party, that were demanding that the leadership go further to the left.
Before it was electorally defeated in 1951, the post-war Labour government descended into crisis.
Once Labour was in opposition, the left developed into a mass movement, fighting for the party leadership. It took the full weight of the trade union bureaucracy to beat it back.
The same pattern repeated itself with the two Labour governments of the 1960s and 1970s.
The right wing policies pursued by the 1974-79 Labour government provoked a massive left wing rebellion after Margaret Thatcher’s 1979 election victory.
Tony Benn became champion of the Labour left, though he was eventually isolated.
The basic power set-up of the Labour Party – the ruling alliance between the parliamentary leadership and the trade union bureaucracy – ensured that the left always lost. The process of betrayal, rebellion and eventual defeat became a mechanism through which the party renewed itself.
Pressure from the left helped the party to keep up a connection with its working class base. The Labour left movements also helped to draw fresh generations of activists into the party.
Despite the fact that Tony Blair and Gordon Brown’s governments have been the most right wing so far, this process has not yet been repeated.
This is not because there are no moves to the left. But they have bypassed Labour.
A handful of Labour MPs have campaigned with principle. But their efforts haven’t been accompanied by a renewal of the left’s base inside the party.
This is partially about how the Labour Party has been stopped from making decisions. But the membership has also changed. Disillusioned activists have dropped out, while the suits and careerists have stayed.
The courting of the rich to back the party has done more than create the odd funding scandal – the rich don’t go on the knocker at election time.
Although Labour has never been an instrument of radical change, its hold on the trade unions leaders is strong. But the support of union members is begrudging at best.
The electoral system, a century of Labour voting, the imbalance of media coverage and other factors make it very difficult for new parties to establish themselves electorally.
But unless there is a credible force to the left, people who hate the war and who believe in public services, not private profit, will face a rotten choice.
They can grudgingly vote Labour – or not vote at all.